refactor patch management and add ownership safeguards

1 files changed, 44 insertions, 1864 deletions

diff --git a/main.py b/main.py
index b1a8079..c5a3e01 100644
--- a/main.py
+++ b/main.py
@@ -1,1663 +1,65 @@
-import decky
-import os
-import subprocess
-import json
-import shutil
-import re
-import filecmp
-import hashlib
-from datetime import datetime, timezone
-from pathlib import Path
-
-OPTISCALER_ARCHIVE_ASSET = {
-    "name": "Optiscaler_0.9.4-final.20260718._MM.7z",
-    "sha256": "575cb4df866116093df75af607e37fd70e10f5163e0f23fd5c804142e80ef0ad",
-    "version": "0.9.4-final.20260718",
-}
-
-FSR4_INT8_ASSET = {
-    "name": "amd_fidelityfx_upscaler_dx12.dll",
-    "sha256": "c7720bc16bede334f59a1a32cd22edbcbbb159685ed5240e61350a5fb0bc8a94",
-    "version": "4.0.2c",
-}
-
-FSR4_OFFICIAL_411_ASSET = {
-    "name": "amdxcffx64.dll",
-    "sha256": "a2b136b6affd35a49b141a936be935f7d5ddc8d8f9b8c9afbe62ff9ddb2538a0",
-    "version": "4.1.1-official",
-}
-
-FSR4_VALVE_411_ASSET = {
-    "name": "amdxcffx64_valve_2.3.0.2913.dll",
-    "sha256": "4e7dc37aebea3a90e3d3cc43e24cb2b54176b2535315f20dbe63b3b7cfc56b1e",
-    "version": "4.1.1-valve-2.3.0.2913",
-}
-
-AMDXC64_RDNA2_ASSET = {
-    "name": "amdxc64.dll",
-    "sha256": "a0a0af61d475e30a70966b3459f3793df772faf8f26ae3261d10554ff592cbd5",
-    "version": "8.18.10.0474",
-}
-
-OPTISCALER_PRE10_ASSET = {
-    "name": "OptiScaler_0.10.0-pre1.20260622_135940.dll",
-    "sha256": "b374b19081cc066365d0c6da4808d768e16469b0cbdfc478b6e95999947d5364",
-    "version": "0.10.0-pre1.20260622_135940",
-}
-
-OPTIPATCHER_ASSET = {
-    "name": "OptiPatcher_rolling.asi",
-    "sha256": "88b9e1be3559737cd205fdf5f2c8550cf1923fb1def4c603e5bf03c3e84131b1",
-    "version": "rolling",
-}
-
-FSR4_UPSCALER_FILENAME = "amd_fidelityfx_upscaler_dx12.dll"
-FSR4_DRIVER_OVERRIDE_FILENAME = "amdxcffx64.dll"
-INSTALL_MANIFEST_FILENAME = "install-manifest.json"
-VERSION_FILENAME = "version.txt"
-DEFAULT_FSR4_VARIANT = "rdna23-int8"
-
-FSR4_VARIANTS = {
-    "rdna23-int8": {
-        "label": "4.0.2c / RDNA2-3 compatibility",
-        "dir_name": "fsr4-rdna2-3",
-        "sha256": "c7720bc16bede334f59a1a32cd22edbcbbb159685ed5240e61350a5fb0bc8a94",
-        "source_asset_name": FSR4_INT8_ASSET["name"],
-        "source_version": FSR4_INT8_ASSET["version"],
-        "uses_archive_native": False,
-        "extra_files": [],
-    },
-    "rdna4-native": {
-        "label": "4.1.1 SDK / RDNA3 dGPU + RDNA4",
-        "dir_name": "fsr4-rdna4",
-        "sha256": "d0dcccc74a43c44ba435b7a369b456e0970d8a4464e4bd683119b374f2c9fb46",
-        "source_asset_name": OPTISCALER_ARCHIVE_ASSET["name"],
-        "source_version": OPTISCALER_ARCHIVE_ASSET["version"],
-        "uses_archive_native": True,
-        "extra_files": [],
-    },
-    "rdna34-official-411": {
-        "label": "4.1.1 driver override / RDNA3-4",
-        "dir_name": "fsr4-rdna3-4-official-411",
-        "sha256": "d0dcccc74a43c44ba435b7a369b456e0970d8a4464e4bd683119b374f2c9fb46",
-        "source_asset_name": OPTISCALER_ARCHIVE_ASSET["name"],
-        "source_version": OPTISCALER_ARCHIVE_ASSET["version"],
-        "uses_archive_native": True,
-        "extra_files": [
-            {
-                "name": FSR4_DRIVER_OVERRIDE_FILENAME,
-                "sha256": FSR4_OFFICIAL_411_ASSET["sha256"],
-                "source_asset_name": FSR4_OFFICIAL_411_ASSET["name"],
-                "source_version": FSR4_OFFICIAL_411_ASSET["version"],
-            }
-        ],
-        "config_overrides": {},
-    },
-    "rdna2-valve-411-pre10": {
-        "label": "4.1.1 Valve RDNA2 compatibility",
-        "dir_name": "fsr4-rdna2-valve-411-pre10",
-        "sha256": "d0dcccc74a43c44ba435b7a369b456e0970d8a4464e4bd683119b374f2c9fb46",
-        "source_asset_name": OPTISCALER_ARCHIVE_ASSET["name"],
-        "source_version": OPTISCALER_ARCHIVE_ASSET["version"],
-        "uses_archive_native": True,
-        "injector": {
-            "name": "OptiScaler.dll",
-            "sha256": OPTISCALER_PRE10_ASSET["sha256"],
-            "source_asset_name": OPTISCALER_PRE10_ASSET["name"],
-            "source_version": OPTISCALER_PRE10_ASSET["version"],
-        },
-        "extra_files": [
-            {
-                "name": FSR4_DRIVER_OVERRIDE_FILENAME,
-                "sha256": FSR4_VALVE_411_ASSET["sha256"],
-                "source_asset_name": FSR4_VALVE_411_ASSET["name"],
-                "source_version": FSR4_VALVE_411_ASSET["version"],
-            },
-            {
-                "name": "amdxc64.dll",
-                "sha256": AMDXC64_RDNA2_ASSET["sha256"],
-                "source_asset_name": AMDXC64_RDNA2_ASSET["name"],
-                "source_version": AMDXC64_RDNA2_ASSET["version"],
-            }
-        ],
-        "config_overrides": {
-            "FSR.Fsr4ForceModel": "2",
-            "Plugins.LoadCustomAmdxc64OnRdna2": "true",
-        },
-    },
-}
-VARIANT_EXTRA_FILENAMES = sorted(
-    {
-        extra_file["name"]
-        for variant in FSR4_VARIANTS.values()
-        for extra_file in variant.get("extra_files", [])
-    }
-)
+"""Decky entry point for the Framegen plugin.
 
-PROXY_DLL_BACKUPS = [
-    "dxgi.dll",
-    "winmm.dll",
-    "dbghelp.dll",
-    "version.dll",
-    "wininet.dll",
-    "winhttp.dll",
-    "OptiScaler.asi",
-]
+Decky-facing methods live here; filesystem, Steam, configuration, and patch
+ownership concerns are implemented in ``backend`` services.
+"""
 
-VALID_DLL_NAMES = set(PROXY_DLL_BACKUPS)
-
-INJECTOR_FILENAMES = [
-    *PROXY_DLL_BACKUPS,
-    "nvngx.dll",
-    "_nvngx.dll",
-    "nvngx-wrapper.dll",
-    "dlss-enabler.dll",
-    "OptiScaler.dll",
-]
-
-PATCH_CLEANUP_FILES = [
-    *INJECTOR_FILENAMES,
-    *VARIANT_EXTRA_FILENAMES,
-    "nvapi64.dll",
-    "nvapi64.dll.b",
-    "nvngx.ini",
-    "dlss-enabler-upscaler.dll",
-    "fakenvapi.log",
-    "OptiScaler.log",
-    "dlssg_to_fsr3.log",
-    "dlssg_to_fsr3_amd_is_better-3.0.dll",
-]
-
-PATCH_FINGERPRINT_FILES = [
-    "FRAMEGEN_PATCH",
-    "OptiScaler.ini",
-    "fakenvapi.dll",
-    "fakenvapi.ini",
-    "dlssg_to_fsr3_amd_is_better.dll",
-    "D3D12_Optiscaler",
-]
-
-ORIGINAL_DLL_BACKUPS = [
-    "d3dcompiler_47.dll",
-    "amd_fidelityfx_dx12.dll",
-    "amd_fidelityfx_framegeneration_dx12.dll",
-    FSR4_UPSCALER_FILENAME,
-    FSR4_DRIVER_OVERRIDE_FILENAME,
-    "amdxc64.dll",
-    "amd_fidelityfx_vk.dll",
-]
-
-RESTORABLE_BACKUP_FILES = [
-    *PROXY_DLL_BACKUPS,
-    *ORIGINAL_DLL_BACKUPS,
-]
-
-SUPPORT_FILES = [
-    "libxess.dll",
-    "libxess_dx11.dll",
-    "libxess_fg.dll",
-    "libxell.dll",
-    "amd_fidelityfx_dx12.dll",
-    "amd_fidelityfx_framegeneration_dx12.dll",
-    "amd_fidelityfx_vk.dll",
-    "dlssg_to_fsr3_amd_is_better.dll",
-    "fakenvapi.dll",
-    "fakenvapi.ini",
-]
+from pathlib import Path
 
-MARKER_FILENAME = "FRAMEGEN_PATCH"
+import decky
 
-BAD_EXE_SUBSTRINGS = [
-    "crashreport",
-    "crashreportclient",
-    "eac",
-    "easyanticheat",
-    "beclient",
-    "eosbootstrap",
-    "benchmark",
-    "uninstall",
-    "setup",
-    "launcher",
-    "updater",
-    "bootstrap",
-    "_redist",
-    "prereq",
-]
+from backend.assets import DEFAULT_FRAMEGEN_BACKEND, DEFAULT_FSR4_VARIANT
+from backend.bundle import BundleManager
+from backend.patcher import PatchManager
+from backend.steam import SteamLibrary
 
-LEGACY_FILES = [
-    "dlssg_to_fsr3.ini",
-    "dlssg_to_fsr3.log",
-    "nvapi64.dll",
-    "nvapi64.dll.b",
-    "fakenvapi.log",
-    "dlss-enabler.dll",
-    "dlss-enabler-upscaler.dll",
-    "dlss-enabler.log",
-    "nvngx.ini",
-    "nvngx-wrapper.dll",
-    "_nvngx.dll",
-    "dlssg_to_fsr3_amd_is_better-3.0.dll",
-    "OptiScaler.asi",
-    "OptiScaler.ini",
-    "OptiScaler.log",
-]
 
 class Plugin:
+    def __init__(self):
+        home = Path(str(decky.HOME))
+        plugin_dir = Path(str(decky.DECKY_PLUGIN_DIR))
+        logger = decky.logger.error
+        self._bundle = BundleManager(home, plugin_dir, logger)
+        self._steam = SteamLibrary(home, logger)
+        self._patcher = PatchManager(home, self._bundle, self._steam, logger)
+
     async def _main(self):
         decky.logger.info("Framegen plugin loaded")
 
     async def _unload(self):
         decky.logger.info("Framegen plugin unloaded.")
-        
-    def _create_renamed_copies(self, source_file, renames_dir):
-        """Create renamed copies of the OptiScaler.dll file"""
-        try:
-            renames_dir.mkdir(exist_ok=True)
-            
-            rename_files = [
-                "dxgi.dll",
-                "winmm.dll",
-                "dbghelp.dll",
-                "version.dll",
-                "wininet.dll",
-                "winhttp.dll",
-                "OptiScaler.asi"
-            ]
-            
-            if source_file.exists():
-                for rename_file in rename_files:
-                    dest_file = renames_dir / rename_file
-                    shutil.copy2(source_file, dest_file)
-                    decky.logger.info(f"Created renamed copy: {dest_file}")
-                return True
-            else:
-                decky.logger.error(f"Source file {source_file} does not exist")
-                return False
-                
-        except Exception as e:
-            decky.logger.error(f"Failed to create renamed copies: {e}")
-            return False
-    
-    def _copy_launcher_scripts(self, assets_dir, extract_path):
-        """Copy launcher scripts from assets directory"""
-        try:
-            # Copy fgmod script
-            fgmod_script_src = assets_dir / "fgmod.sh"
-            fgmod_script_dest = extract_path / "fgmod"
-            if fgmod_script_src.exists():
-                shutil.copy2(fgmod_script_src, fgmod_script_dest)
-                fgmod_script_dest.chmod(0o755)
-                decky.logger.info(f"Copied fgmod script to {fgmod_script_dest}")
-            
-            # Copy uninstaller script
-            uninstaller_src = assets_dir / "fgmod-uninstaller.sh"
-            uninstaller_dest = extract_path / "fgmod-uninstaller.sh"
-            if uninstaller_src.exists():
-                shutil.copy2(uninstaller_src, uninstaller_dest)
-                uninstaller_dest.chmod(0o755)
-                decky.logger.info(f"Copied uninstaller script to {uninstaller_dest}")
-
-            # Copy optiscaler config updater script
-            optiscaler_config_updater_src = assets_dir / "update-optiscaler-config.py"
-            optiscaler_config_updater_dest = extract_path / "update-optiscaler-config.py"
-            if optiscaler_config_updater_src.exists():
-                shutil.copy2(optiscaler_config_updater_src, optiscaler_config_updater_dest)
-                optiscaler_config_updater_dest.chmod(0o755)
-                decky.logger.info(f"Copied update-optiscaler-config.py script to {optiscaler_config_updater_dest}")
-                
-            return True
-        except Exception as e:
-            decky.logger.error(f"Failed to copy launcher scripts: {e}")
-            return False
-    
-    def _files_match(self, file_a: Path, file_b: Path) -> bool:
-        try:
-            return file_a.exists() and file_b.exists() and filecmp.cmp(file_a, file_b, shallow=False)
-        except Exception:
-            return False
-
-    def _is_bundled_proxy_copy(self, file_path: Path, fgmod_path: Path) -> bool:
-        bundled_copy = fgmod_path / "renames" / file_path.name
-        return self._files_match(file_path, bundled_copy)
-
-    def _has_patch_fingerprint(self, directory: Path) -> bool:
-        return any((directory / filename).exists() for filename in PATCH_FINGERPRINT_FILES)
-
-    def _backup_preexisting_proxy_files(self, directory: Path, fgmod_path: Path) -> list[str]:
-        backed_up: list[str] = []
-        already_patched = self._has_patch_fingerprint(directory)
-        for filename in PROXY_DLL_BACKUPS:
-            source = directory / filename
-            backup = directory / f"{filename}.b"
-            if not source.exists() or backup.exists():
-                continue
-            if already_patched or self._is_bundled_proxy_copy(source, fgmod_path):
-                continue
-            shutil.move(source, backup)
-            backed_up.append(filename)
-        return backed_up
-
-    def _file_sha256(self, path: Path) -> str:
-        digest = hashlib.sha256()
-        with open(path, "rb") as f:
-            for chunk in iter(lambda: f.read(1024 * 1024), b""):
-                digest.update(chunk)
-        return digest.hexdigest()
-
-    def _read_json_file(self, path: Path) -> dict:
-        try:
-            with open(path, "r", encoding="utf-8") as f:
-                data = json.load(f)
-            return data if isinstance(data, dict) else {}
-        except Exception:
-            return {}
-
-    def _write_json_file(self, path: Path, payload: dict) -> None:
-        with open(path, "w", encoding="utf-8") as f:
-            json.dump(payload, f, indent=2)
-
-    def _extract_archive(self, archive_path: Path, output_dir: Path, members: list[str] | None = None) -> None:
-        output_dir.mkdir(parents=True, exist_ok=True)
-        extract_cmd = [
-            "7z",
-            "x",
-            "-y",
-            "-o" + str(output_dir),
-            str(archive_path),
-        ]
-        if members:
-            extract_cmd.extend(members)
-
-        clean_env = os.environ.copy()
-        clean_env["LD_LIBRARY_PATH"] = ""
-        result = subprocess.run(
-            extract_cmd,
-            capture_output=True,
-            text=True,
-            check=False,
-            env=clean_env,
-        )
-        if result.returncode != 0:
-            raise RuntimeError(result.stderr or result.stdout or f"Failed to extract {archive_path.name}")
-
-    def _verify_bundled_asset(self, path: Path, expected_sha256: str, description: str) -> str:
-        actual_sha256 = self._file_sha256(path)
-        if actual_sha256.lower() != expected_sha256.lower():
-            raise RuntimeError(
-                f"{description} hash mismatch: expected {expected_sha256}, got {actual_sha256}"
-            )
-        return actual_sha256
-
-    def _install_manifest_path(self, fgmod_path: Path) -> Path:
-        return fgmod_path / INSTALL_MANIFEST_FILENAME
-
-    def _load_install_manifest(self, fgmod_path: Path) -> dict:
-        return self._read_json_file(self._install_manifest_path(fgmod_path))
-
-    def _normalize_fsr4_variant(self, fsr4_variant: str | None) -> str:
-        variant = str(fsr4_variant or "").strip()
-        if variant in FSR4_VARIANTS:
-            return variant
-        return DEFAULT_FSR4_VARIANT
-
-    def _selected_fsr4_variant(self, fgmod_path: Path, requested_variant: str | None = None) -> str:
-        normalized_requested = str(requested_variant or "").strip()
-        if normalized_requested in FSR4_VARIANTS:
-            return normalized_requested
-        manifest = self._load_install_manifest(fgmod_path)
-        manifest_variant = str(manifest.get("selected_default_variant") or "").strip()
-        if manifest_variant in FSR4_VARIANTS:
-            return manifest_variant
-        return DEFAULT_FSR4_VARIANT
-
-    def _fsr4_variant_info(self, fsr4_variant: str | None) -> dict:
-        return FSR4_VARIANTS[self._normalize_fsr4_variant(fsr4_variant)]
-
-    def _fsr4_variant_dir(self, fgmod_path: Path, fsr4_variant: str | None) -> Path:
-        variant_id = self._normalize_fsr4_variant(fsr4_variant)
-        return fgmod_path / FSR4_VARIANTS[variant_id]["dir_name"]
-
-    def _fsr4_variant_path(self, fgmod_path: Path, fsr4_variant: str | None) -> Path:
-        return self._fsr4_variant_dir(fgmod_path, fsr4_variant) / FSR4_UPSCALER_FILENAME
-
-    def _fsr4_variant_extra_files(self, fsr4_variant: str | None) -> list[dict]:
-        variant = self._fsr4_variant_info(fsr4_variant)
-        return list(variant.get("extra_files") or [])
-
-    def _fsr4_variant_extra_file_path(self, fgmod_path: Path, fsr4_variant: str | None, filename: str) -> Path:
-        return self._fsr4_variant_dir(fgmod_path, fsr4_variant) / filename
-
-    def _fsr4_variant_injector_info(self, fsr4_variant: str | None) -> dict | None:
-        variant = self._fsr4_variant_info(fsr4_variant)
-        injector = variant.get("injector")
-        return injector if isinstance(injector, dict) else None
-
-    def _fsr4_variant_injector_path(self, fgmod_path: Path, fsr4_variant: str | None) -> Path | None:
-        injector = self._fsr4_variant_injector_info(fsr4_variant)
-        if not injector:
-            return None
-        return self._fsr4_variant_dir(fgmod_path, fsr4_variant) / injector.get("name", "OptiScaler.dll")
-
-    def _fsr4_variant_renamed_proxy_path(self, fgmod_path: Path, fsr4_variant: str | None, dll_name: str) -> Path | None:
-        if not self._fsr4_variant_injector_info(fsr4_variant):
-            return None
-        return self._fsr4_variant_dir(fgmod_path, fsr4_variant) / "renames" / dll_name
-
-    def _fsr4_variant_config_overrides(self, fsr4_variant: str | None) -> dict:
-        variant = self._fsr4_variant_info(fsr4_variant)
-        overrides = variant.get("config_overrides") or {}
-        return dict(overrides) if isinstance(overrides, dict) else {}
-
-    def _split_ini_override_key(self, raw_key: str) -> tuple[str | None, str]:
-        key = str(raw_key).strip()
-        if "." in key:
-            section, section_key = key.split(".", 1)
-            section = section.strip()
-            section_key = section_key.strip()
-            if section and section_key:
-                return section, section_key
-        return None, key
-
-    def _apply_optiscaler_ini_overrides(self, ini_file: Path, overrides: dict) -> bool:
-        if not overrides:
-            return True
-        try:
-            content = ini_file.read_text(encoding="utf-8", errors="replace")
-            newline = "\r\n" if "\r\n" in content else "\n"
-            lines = content.splitlines(keepends=True)
-            section_pattern = re.compile(r"^\s*\[(?P<section>[^\]]+)\]\s*$")
-
-            def ensure_trailing_newline() -> None:
-                if lines and not lines[-1].endswith(("\n", "\r")):
-                    lines[-1] += newline
-
-            def upsert(section: str | None, key: str, value: str) -> None:
-                replacement = f"{key}={value}"
-                key_pattern = re.compile(rf"^(\s*{re.escape(key)}\s*)=.*$")
-
-                if section is None:
-                    for idx, line in enumerate(lines):
-                        if key_pattern.match(line):
-                            line_ending = "\r\n" if line.endswith("\r\n") else ("\n" if line.endswith("\n") else newline)
-                            lines[idx] = f"{replacement}{line_ending}"
-                            return
-                    ensure_trailing_newline()
-                    lines.append(f"{replacement}{newline}")
-                    return
-
-                in_section = False
-                insert_at = None
-                for idx, line in enumerate(lines):
-                    match = section_pattern.match(line.strip())
-                    if match:
-                        if in_section:
-                            insert_at = idx
-                            break
-                        if match.group("section") == section:
-                            in_section = True
-                            continue
-                    if in_section and key_pattern.match(line):
-                        line_ending = "\r\n" if line.endswith("\r\n") else ("\n" if line.endswith("\n") else newline)
-                        lines[idx] = f"{replacement}{line_ending}"
-                        return
-
-                if in_section:
-                    if insert_at is None:
-                        ensure_trailing_newline()
-                        insert_at = len(lines)
-                    lines.insert(insert_at, f"{replacement}{newline}")
-                    return
-
-                ensure_trailing_newline()
-                if lines and lines[-1].strip():
-                    lines.append(newline)
-                lines.append(f"[{section}]{newline}")
-                lines.append(f"{replacement}{newline}")
-
-            for raw_key, raw_value in overrides.items():
-                section, key = self._split_ini_override_key(str(raw_key))
-                value = str(raw_value).strip()
-                if key:
-                    upsert(section, key, value)
-
-            ini_file.write_text("".join(lines), encoding="utf-8")
-            return True
-        except Exception as exc:
-            decky.logger.error(f"Failed to apply OptiScaler.ini overrides to {ini_file}: {exc}")
-            return False
-
-    def _sync_variant_root_extra_files(self, fgmod_path: Path, fsr4_variant: str | None) -> None:
-        selected_extra_files = {extra_file["name"]: extra_file for extra_file in self._fsr4_variant_extra_files(fsr4_variant)}
-        for filename in VARIANT_EXTRA_FILENAMES:
-            root_path = fgmod_path / filename
-            if filename not in selected_extra_files:
-                if root_path.exists():
-                    root_path.unlink()
-                continue
-            source_path = self._fsr4_variant_extra_file_path(fgmod_path, fsr4_variant, filename)
-            if not source_path.exists():
-                raise FileNotFoundError(f"Prepared FSR4 variant extra file missing: {source_path}")
-            shutil.copy2(source_path, root_path)
-
-    def _activate_default_fsr4_variant(self, fgmod_path: Path, fsr4_variant: str | None) -> str:
-        variant_id = self._normalize_fsr4_variant(fsr4_variant)
-        variant_path = self._fsr4_variant_path(fgmod_path, variant_id)
-        if not variant_path.exists():
-            raise FileNotFoundError(f"Prepared FSR4 variant missing: {variant_path}")
-        shutil.copy2(variant_path, fgmod_path / FSR4_UPSCALER_FILENAME)
-        self._sync_variant_root_extra_files(fgmod_path, variant_id)
-        return variant_id
-
-    def _detect_fsr4_variant(self, directory: Path, upscaler_sha256: str | None) -> str | None:
-        for variant_id, variant in FSR4_VARIANTS.items():
-            extra_files = list(variant.get("extra_files") or [])
-            if not extra_files:
-                continue
-            if not upscaler_sha256 or str(variant.get("sha256") or "").lower() != str(upscaler_sha256).lower():
-                continue
-            all_match = True
-            for extra_file in extra_files:
-                file_path = directory / extra_file["name"]
-                if not file_path.exists() or self._file_sha256(file_path).lower() != extra_file["sha256"].lower():
-                    all_match = False
-                    break
-            if all_match:
-                return variant_id
-
-        if not upscaler_sha256:
-            return None
-        normalized_sha = str(upscaler_sha256).lower()
-        for variant_id, variant in FSR4_VARIANTS.items():
-            if variant.get("extra_files"):
-                continue
-            if str(variant.get("sha256") or "").lower() == normalized_sha:
-                return variant_id
-        return None
-
-    def _fgmod_version(self, fgmod_path: Path) -> str | None:
-        manifest = self._load_install_manifest(fgmod_path)
-        optiscaler = manifest.get("optiscaler") if isinstance(manifest, dict) else None
-        if isinstance(optiscaler, dict) and optiscaler.get("version"):
-            return str(optiscaler.get("version"))
-        version_file = fgmod_path / VERSION_FILENAME
-        try:
-            if version_file.exists():
-                return version_file.read_text(encoding="utf-8").strip() or None
-        except Exception:
-            return None
-        return None
-
-    def _managed_support_candidate_paths(self, fgmod_path: Path, filename: str) -> list[Path]:
-        candidates: list[Path] = []
-        if filename == FSR4_UPSCALER_FILENAME:
-            candidates.append(fgmod_path / FSR4_UPSCALER_FILENAME)
-            for variant_id in FSR4_VARIANTS:
-                candidates.append(self._fsr4_variant_path(fgmod_path, variant_id))
-        else:
-            candidates.append(fgmod_path / filename)
-            for variant_id in FSR4_VARIANTS:
-                for extra_file in self._fsr4_variant_extra_files(variant_id):
-                    if extra_file["name"] == filename:
-                        candidates.append(self._fsr4_variant_extra_file_path(fgmod_path, variant_id, filename))
-        unique: list[Path] = []
-        seen: set[str] = set()
-        for candidate in candidates:
-            key = str(candidate)
-            if key not in seen:
-                unique.append(candidate)
-                seen.add(key)
-        return unique
-
-    def _is_managed_support_file(self, path: Path, fgmod_path: Path) -> bool:
-        if not path.exists():
-            return False
-        for candidate in self._managed_support_candidate_paths(fgmod_path, path.name):
-            if self._files_match(path, candidate):
-                return True
-        return False
-
-    def _migrate_optiscaler_ini(self, ini_file):
-        """Migrate pre-v0.9-final OptiScaler.ini: replace FGType with FGInput + FGOutput.
-
-        v0.9-final split the single FGType key into separate FGInput and FGOutput keys.
-        Games already patched with an older build will have FGType=<value> in their
-        per-game INI but no FGInput/FGOutput entries, causing the new DLL to silently
-        fall back to nofg.  This migration runs at patch-time and at every fgmod.sh
-        launch so users never have to manually touch their INI.
-        """
-        try:
-            if not ini_file.exists():
-                return False
-
-            with open(ini_file, 'r') as f:
-                content = f.read()
-
-            fg_type_match = re.search(r'^FGType\s*=\s*(\S+)', content, re.MULTILINE)
-            if not fg_type_match:
-                return True  # Nothing to migrate
-
-            fg_value = fg_type_match.group(1)
-
-            if re.search(r'^FGInput\s*=', content, re.MULTILINE):
-                # FGInput already present (INI already in v0.9-final format);
-                # just remove the now-unknown FGType line.
-                content = re.sub(r'^FGType\s*=\s*\S+\n?', '', content, flags=re.MULTILINE)
-                decky.logger.info(f"Removed stale FGType from {ini_file} (FGInput already present)")
-            else:
-                # Replace the single FGType=X line with FGInput=X then FGOutput=X
-                content = re.sub(
-                    r'^FGType\s*=\s*\S+',
-                    f'FGInput={fg_value}\nFGOutput={fg_value}',
-                    content,
-                    flags=re.MULTILINE
-                )
-                decky.logger.info(f"Migrated FGType={fg_value} → FGInput={fg_value}, FGOutput={fg_value} in {ini_file}")
-
-            with open(ini_file, 'w') as f:
-                f.write(content)
-            return True
-        except Exception as e:
-            decky.logger.error(f"Failed to migrate OptiScaler.ini: {e}")
-            return False
-
-    def _disable_hq_font_auto(self, ini_file):
-        """Disable the new HQ font auto mode to avoid missing font assertions on Wine/Proton."""
-        try:
-            if not ini_file.exists():
-                decky.logger.warning(f"OptiScaler.ini not found at {ini_file}")
-                return False
-
-            with open(ini_file, 'r') as f:
-                content = f.read()
-
-            updated_content = re.sub(r'UseHQFont\s*=\s*auto', 'UseHQFont=false', content)
-            if updated_content != content:
-                with open(ini_file, 'w') as f:
-                    f.write(updated_content)
-                decky.logger.info("Set UseHQFont=false to avoid missing font assertions")
-
-            return True
-        except Exception as e:
-            decky.logger.error(f"Failed to update HQ font setting in OptiScaler.ini: {e}")
-            return False
-
-    def _modify_optiscaler_ini(self, ini_file):
-        """Modify OptiScaler.ini to set FG defaults, ASI plugin settings, and safe font defaults."""
-        try:
-            if ini_file.exists():
-                with open(ini_file, 'r') as f:
-                    content = f.read()
-                
-                # Replace FGInput=auto with FGInput=nukems (final v0.9+ split FGType into FGInput/FGOutput)
-                updated_content = re.sub(r'FGInput\s*=\s*auto', 'FGInput=nukems', content)
-
-                # Replace FGOutput=auto with FGOutput=nukems
-                updated_content = re.sub(r'FGOutput\s*=\s*auto', 'FGOutput=nukems', updated_content)
-                
-                # Replace Fsr4Update=auto with Fsr4Update=true
-                updated_content = re.sub(r'Fsr4Update\s*=\s*auto', 'Fsr4Update=true', updated_content)
-                
-                # Replace LoadAsiPlugins=auto with LoadAsiPlugins=true
-                updated_content = re.sub(r'LoadAsiPlugins\s*=\s*auto', 'LoadAsiPlugins=true', updated_content)
-
-                # Disable new HQ font auto mode to avoid missing font assertions on Proton
-                updated_content = re.sub(r'UseHQFont\s*=\s*auto', 'UseHQFont=false', updated_content)
-                
-                with open(ini_file, 'w') as f:
-                    f.write(updated_content)
-                
-                decky.logger.info("Modified OptiScaler.ini to set FGInput=nukems, FGOutput=nukems, Fsr4Update=true, LoadAsiPlugins=true, UseHQFont=false")
-                return True
-            else:
-                decky.logger.warning(f"OptiScaler.ini not found at {ini_file}")
-                return False
-        except Exception as e:
-            decky.logger.error(f"Failed to modify OptiScaler.ini: {e}")
-            return False
-
-    async def extract_static_optiscaler(self, selected_default_variant: str = DEFAULT_FSR4_VARIANT) -> dict:
-        """Prepare the shared ~/fgmod bundle with all bundled FSR4 runtime variants."""
-        try:
-            decky.logger.info("Starting extract_static_optiscaler method")
-
-            bin_path = Path(decky.DECKY_PLUGIN_DIR) / "bin"
-            extract_path = Path(decky.HOME) / "fgmod"
-            assets_dir = Path(decky.DECKY_PLUGIN_DIR) / "assets"
-            selected_default_variant = self._normalize_fsr4_variant(selected_default_variant)
-
-            if not bin_path.exists():
-                return {"status": "error", "message": f"Bin directory not found: {bin_path}"}
-
-            optiscaler_archive = bin_path / OPTISCALER_ARCHIVE_ASSET["name"]
-            fsr4_int8_src = bin_path / FSR4_INT8_ASSET["name"]
-            fsr4_official_411_src = bin_path / FSR4_OFFICIAL_411_ASSET["name"]
-            fsr4_valve_411_src = bin_path / FSR4_VALVE_411_ASSET["name"]
-            amdxc64_rdna2_src = bin_path / AMDXC64_RDNA2_ASSET["name"]
-            optiscaler_pre10_src = bin_path / OPTISCALER_PRE10_ASSET["name"]
-            optipatcher_src = bin_path / OPTIPATCHER_ASSET["name"]
-            for required_path, asset in [
-                (optiscaler_archive, OPTISCALER_ARCHIVE_ASSET),
-                (fsr4_int8_src, FSR4_INT8_ASSET),
-                (fsr4_official_411_src, FSR4_OFFICIAL_411_ASSET),
-                (fsr4_valve_411_src, FSR4_VALVE_411_ASSET),
-                (amdxc64_rdna2_src, AMDXC64_RDNA2_ASSET),
-                (optiscaler_pre10_src, OPTISCALER_PRE10_ASSET),
-                (optipatcher_src, OPTIPATCHER_ASSET),
-            ]:
-                if not required_path.exists():
-                    return {
-                        "status": "error",
-                        "message": f"Required bundled asset missing: {asset['name']}",
-                    }
-                self._verify_bundled_asset(required_path, asset["sha256"], asset["name"])
-
-            if extract_path.exists():
-                shutil.rmtree(extract_path)
-            extract_path.mkdir(parents=True, exist_ok=True)
-
-            self._extract_archive(optiscaler_archive, extract_path)
-
-            source_file = extract_path / "OptiScaler.dll"
-            renames_dir = extract_path / "renames"
-            if not self._create_renamed_copies(source_file, renames_dir):
-                return {"status": "error", "message": "Failed to prepare renamed OptiScaler proxies."}
-
-            if not self._copy_launcher_scripts(assets_dir, extract_path):
-                return {"status": "error", "message": "Failed to copy launcher scripts."}
-
-            plugins_dir = extract_path / "plugins"
-            plugins_dir.mkdir(parents=True, exist_ok=True)
-            optipatcher_dst = plugins_dir / "OptiPatcher.asi"
-            shutil.copy2(optipatcher_src, optipatcher_dst)
-            optipatcher_sha256 = self._verify_bundled_asset(
-                optipatcher_dst,
-                OPTIPATCHER_ASSET["sha256"],
-                "Prepared OptiPatcher plugin",
-            )
-
-            ini_file = extract_path / "OptiScaler.ini"
-            self._modify_optiscaler_ini(ini_file)
-
-            native_upscaler_root = extract_path / FSR4_UPSCALER_FILENAME
-            native_upscaler_sha256 = self._verify_bundled_asset(
-                native_upscaler_root,
-                FSR4_VARIANTS["rdna4-native"]["sha256"],
-                "Archive-native FSR4 upscaler",
-            )
 
-            rdna4_dir = extract_path / FSR4_VARIANTS["rdna4-native"]["dir_name"]
-            rdna4_dir.mkdir(parents=True, exist_ok=True)
-            rdna4_upscaler = rdna4_dir / FSR4_UPSCALER_FILENAME
-            shutil.copy2(native_upscaler_root, rdna4_upscaler)
-            self._verify_bundled_asset(
-                rdna4_upscaler,
-                FSR4_VARIANTS["rdna4-native"]["sha256"],
-                "Prepared rdna4-native FSR4 upscaler",
-            )
-
-            official_411_dir = extract_path / FSR4_VARIANTS["rdna34-official-411"]["dir_name"]
-            official_411_dir.mkdir(parents=True, exist_ok=True)
-            official_411_upscaler = official_411_dir / FSR4_UPSCALER_FILENAME
-            shutil.copy2(native_upscaler_root, official_411_upscaler)
-            self._verify_bundled_asset(
-                official_411_upscaler,
-                FSR4_VARIANTS["rdna34-official-411"]["sha256"],
-                "Prepared rdna34-official-411 FSR4 upscaler",
-            )
-            self._verify_bundled_asset(
-                fsr4_official_411_src,
-                FSR4_OFFICIAL_411_ASSET["sha256"],
-                "Bundled rdna34-official-411 driver override",
-            )
-            official_411_driver = official_411_dir / FSR4_DRIVER_OVERRIDE_FILENAME
-            shutil.copy2(fsr4_official_411_src, official_411_driver)
-            self._verify_bundled_asset(
-                official_411_driver,
-                FSR4_OFFICIAL_411_ASSET["sha256"],
-                "Prepared rdna34-official-411 driver override",
-            )
-
-            rdna2_valve_dir = extract_path / FSR4_VARIANTS["rdna2-valve-411-pre10"]["dir_name"]
-            rdna2_valve_dir.mkdir(parents=True, exist_ok=True)
-            rdna2_valve_upscaler = rdna2_valve_dir / FSR4_UPSCALER_FILENAME
-            shutil.copy2(native_upscaler_root, rdna2_valve_upscaler)
-            self._verify_bundled_asset(
-                rdna2_valve_upscaler,
-                FSR4_VARIANTS["rdna2-valve-411-pre10"]["sha256"],
-                "Prepared rdna2-valve-411-pre10 FSR4 upscaler",
-            )
-            self._verify_bundled_asset(
-                fsr4_valve_411_src,
-                FSR4_VALVE_411_ASSET["sha256"],
-                "Bundled rdna2-valve-411-pre10 driver override",
-            )
-            rdna2_valve_driver = rdna2_valve_dir / FSR4_DRIVER_OVERRIDE_FILENAME
-            shutil.copy2(fsr4_valve_411_src, rdna2_valve_driver)
-            self._verify_bundled_asset(
-                rdna2_valve_driver,
-                FSR4_VALVE_411_ASSET["sha256"],
-                "Prepared rdna2-valve-411-pre10 driver override",
-            )
-            self._verify_bundled_asset(
-                amdxc64_rdna2_src,
-                AMDXC64_RDNA2_ASSET["sha256"],
-                "Bundled rdna2-valve-411-pre10 amdxc64 override",
-            )
-            rdna2_valve_amdxc64 = rdna2_valve_dir / "amdxc64.dll"
-            shutil.copy2(amdxc64_rdna2_src, rdna2_valve_amdxc64)
-            self._verify_bundled_asset(
-                rdna2_valve_amdxc64,
-                AMDXC64_RDNA2_ASSET["sha256"],
-                "Prepared rdna2-valve-411-pre10 amdxc64 override",
-            )
-            self._verify_bundled_asset(
-                optiscaler_pre10_src,
-                OPTISCALER_PRE10_ASSET["sha256"],
-                "Bundled rdna2-valve-411-pre10 OptiScaler injector",
-            )
-            rdna2_valve_injector = rdna2_valve_dir / "OptiScaler.dll"
-            shutil.copy2(optiscaler_pre10_src, rdna2_valve_injector)
-            self._verify_bundled_asset(
-                rdna2_valve_injector,
-                OPTISCALER_PRE10_ASSET["sha256"],
-                "Prepared rdna2-valve-411-pre10 OptiScaler injector",
-            )
-            if not self._create_renamed_copies(rdna2_valve_injector, rdna2_valve_dir / "renames"):
-                return {"status": "error", "message": "Failed to prepare renamed pre10 OptiScaler proxies."}
-
-            rdna23_dir = extract_path / FSR4_VARIANTS["rdna23-int8"]["dir_name"]
-            rdna23_dir.mkdir(parents=True, exist_ok=True)
-            self._verify_bundled_asset(
-                fsr4_int8_src,
-                FSR4_VARIANTS["rdna23-int8"]["sha256"],
-                "Bundled rdna23-int8 FSR4 upscaler",
-            )
-            shutil.copy2(fsr4_int8_src, rdna23_dir / FSR4_UPSCALER_FILENAME)
-            self._verify_bundled_asset(
-                rdna23_dir / FSR4_UPSCALER_FILENAME,
-                FSR4_VARIANTS["rdna23-int8"]["sha256"],
-                "Prepared rdna23-int8 FSR4 upscaler",
-            )
-
-            selected_default_variant = self._activate_default_fsr4_variant(extract_path, selected_default_variant)
-            active_upscaler_sha256 = self._file_sha256(extract_path / FSR4_UPSCALER_FILENAME)
-
-            version_file = extract_path / VERSION_FILENAME
-            version_file.write_text(OPTISCALER_ARCHIVE_ASSET["version"], encoding="utf-8")
-
-            install_manifest = {
-                "schema_version": 1,
-                "installed_at": datetime.now(timezone.utc).isoformat(),
-                "optiscaler": {
-                    "asset_name": OPTISCALER_ARCHIVE_ASSET["name"],
-                    "version": OPTISCALER_ARCHIVE_ASSET["version"],
-                    "sha256": OPTISCALER_ARCHIVE_ASSET["sha256"],
-                    "native_upscaler_sha256": native_upscaler_sha256,
-                },
-                "optipatcher": {
-                    "asset_name": OPTIPATCHER_ASSET["name"],
-                    "version": OPTIPATCHER_ASSET["version"],
-                    "sha256": optipatcher_sha256,
-                    "target_path": str(optipatcher_dst.relative_to(extract_path)),
-                },
-                "fsr4_variants": {
-                    variant_id: {
-                        "label": variant["label"],
-                        "dir_name": variant["dir_name"],
-                        "path": str((Path(variant["dir_name"]) / FSR4_UPSCALER_FILENAME).as_posix()),
-                        "sha256": variant["sha256"],
-                        "source_asset_name": variant["source_asset_name"],
-                        "source_version": variant["source_version"],
-                        "uses_archive_native": bool(variant["uses_archive_native"]),
-                        "injector": (
-                            {
-                                "name": variant["injector"]["name"],
-                                "sha256": variant["injector"]["sha256"],
-                                "source_asset_name": variant["injector"]["source_asset_name"],
-                                "source_version": variant["injector"]["source_version"],
-                                "path": str((Path(variant["dir_name"]) / variant["injector"]["name"]).as_posix()),
-                            }
-                            if isinstance(variant.get("injector"), dict)
-                            else None
-                        ),
-                        "config_overrides": dict(variant.get("config_overrides") or {}),
-                        "extra_files": [
-                            {
-                                "name": extra_file["name"],
-                                "sha256": extra_file["sha256"],
-                                "source_asset_name": extra_file["source_asset_name"],
-                                "source_version": extra_file["source_version"],
-                                "path": str((Path(variant["dir_name"]) / extra_file["name"]).as_posix()),
-                            }
-                            for extra_file in variant.get("extra_files", [])
-                        ],
-                    }
-                    for variant_id, variant in FSR4_VARIANTS.items()
-                },
-                "selected_default_variant": selected_default_variant,
-                "active_root_upscaler": {
-                    "path": FSR4_UPSCALER_FILENAME,
-                    "sha256": active_upscaler_sha256,
-                    "variant": selected_default_variant,
-                },
-            }
-            self._write_json_file(self._install_manifest_path(extract_path), install_manifest)
+    async def extract_static_optiscaler(
+        self,
+        selected_default_variant: str = DEFAULT_FSR4_VARIANT,
+        framegen_backend: str = DEFAULT_FRAMEGEN_BACKEND,
+    ) -> dict:
+        return self._bundle.extract_static_optiscaler(selected_default_variant, framegen_backend)
 
-            return {
-                "status": "success",
-                "message": f"Successfully extracted OptiScaler {OPTISCALER_ARCHIVE_ASSET['version']} to ~/fgmod",
-                "version": OPTISCALER_ARCHIVE_ASSET["version"],
-                "selected_default_variant": selected_default_variant,
-                "selected_default_variant_label": FSR4_VARIANTS[selected_default_variant]["label"],
-            }
-        except Exception as e:
-            decky.logger.error(f"Extract failed with exception: {str(e)}")
-            import traceback
-            decky.logger.error(f"Traceback: {traceback.format_exc()}")
-            return {"status": "error", "message": f"Extract failed: {str(e)}"}
+    async def run_install_fgmod(
+        self,
+        selected_default_variant: str = DEFAULT_FSR4_VARIANT,
+        framegen_backend: str = DEFAULT_FRAMEGEN_BACKEND,
+    ) -> dict:
+        return self._bundle.run_install(selected_default_variant, framegen_backend)
 
     async def run_uninstall_fgmod(self) -> dict:
-        try:
-            # Remove fgmod directory
-            fgmod_path = Path(decky.HOME) / "fgmod"
-            
-            if fgmod_path.exists():
-                shutil.rmtree(fgmod_path)
-                decky.logger.info(f"Removed directory: {fgmod_path}")
-                return {
-                    "status": "success", 
-                    "output": "Successfully removed fgmod directory"
-                }
-            else:
-                return {
-                    "status": "success", 
-                    "output": "No fgmod directory found to remove"
-                }
-            
-        except Exception as e:
-            decky.logger.error(f"Uninstall error: {str(e)}")
-            return {
-                "status": "error", 
-                "message": f"Uninstall failed: {str(e)}", 
-                "output": str(e)
-            }
+        return self._bundle.uninstall()
 
     async def set_default_fsr4_variant(self, selected_default_variant: str = DEFAULT_FSR4_VARIANT) -> dict:
-        try:
-            fgmod_path = Path(decky.HOME) / "fgmod"
-            if not fgmod_path.exists():
-                return {"status": "error", "message": "OptiScaler bundle not installed. Run Install first."}
-
-            selected_default_variant = self._normalize_fsr4_variant(selected_default_variant)
-            manifest = self._load_install_manifest(fgmod_path)
-            if not manifest:
-                return {"status": "error", "message": "Install manifest missing. Reinstall OptiScaler."}
+        return self._bundle.set_default_variant(selected_default_variant)
 
-            selected_default_variant = self._activate_default_fsr4_variant(fgmod_path, selected_default_variant)
-            active_upscaler_sha256 = self._file_sha256(fgmod_path / FSR4_UPSCALER_FILENAME)
-            manifest["selected_default_variant"] = selected_default_variant
-            manifest["active_root_upscaler"] = {
-                "path": FSR4_UPSCALER_FILENAME,
-                "sha256": active_upscaler_sha256,
-                "variant": selected_default_variant,
-            }
-            manifest["updated_at"] = datetime.now(timezone.utc).isoformat()
-            self._write_json_file(self._install_manifest_path(fgmod_path), manifest)
-            return {
-                "status": "success",
-                "output": f"Default FSR4 runtime switched to {FSR4_VARIANTS[selected_default_variant]['label']}.",
-                "version": self._fgmod_version(fgmod_path),
-                "selected_default_variant": selected_default_variant,
-                "selected_default_variant_label": FSR4_VARIANTS[selected_default_variant]["label"],
-            }
-        except Exception as e:
-            decky.logger.error(f"Failed to switch default FSR4 runtime: {e}")
-            return {"status": "error", "message": f"Failed to switch default FSR4 runtime: {e}"}
-
-    async def run_install_fgmod(self, selected_default_variant: str = DEFAULT_FSR4_VARIANT) -> dict:
-        try:
-            decky.logger.info("Starting OptiScaler installation from static bundle")
-            selected_default_variant = self._normalize_fsr4_variant(selected_default_variant)
-
-            extract_result = await self.extract_static_optiscaler(selected_default_variant)
-            if extract_result["status"] != "success":
-                return {
-                    "status": "error",
-                    "message": f"OptiScaler extraction failed: {extract_result.get('message', 'Unknown error')}"
-                }
-
-            return {
-                "status": "success",
-                "output": (
-                    "Successfully installed OptiScaler "
-                    f"{extract_result.get('version', OPTISCALER_ARCHIVE_ASSET['version'])} "
-                    f"with {extract_result.get('selected_default_variant_label', FSR4_VARIANTS[selected_default_variant]['label'])}."
-                ),
-                "version": extract_result.get("version", OPTISCALER_ARCHIVE_ASSET["version"]),
-                "selected_default_variant": extract_result.get("selected_default_variant", selected_default_variant),
-                "selected_default_variant_label": extract_result.get(
-                    "selected_default_variant_label",
-                    FSR4_VARIANTS[selected_default_variant]["label"],
-                ),
-            }
-
-        except Exception as e:
-            decky.logger.error(f"Unexpected error during installation: {str(e)}")
-            return {
-                "status": "error",
-                "message": f"Installation failed: {str(e)}"
-            }
+    async def set_framegen_backend(self, framegen_backend: str = DEFAULT_FRAMEGEN_BACKEND) -> dict:
+        return self._bundle.set_framegen_backend(framegen_backend)
 
     async def check_fgmod_path(self) -> dict:
-        path = Path(decky.HOME) / "fgmod"
-        required_files = [
-            "OptiScaler.dll",
-            "OptiScaler.ini",
-            "dlssg_to_fsr3_amd_is_better.dll",
-            "fakenvapi.dll",
-            "fakenvapi.ini",
-            "amd_fidelityfx_dx12.dll",
-            "amd_fidelityfx_framegeneration_dx12.dll",
-            FSR4_UPSCALER_FILENAME,
-            "amd_fidelityfx_vk.dll",
-            "libxess.dll",
-            "libxess_dx11.dll",
-            "libxess_fg.dll",
-            "libxell.dll",
-            "fgmod",
-            "fgmod-uninstaller.sh",
-            "update-optiscaler-config.py",
-            INSTALL_MANIFEST_FILENAME,
-        ]
-
-        if not path.exists():
-            return {"exists": False}
-
-        for file_name in required_files:
-            if not path.joinpath(file_name).exists():
-                return {"exists": False}
-
-        plugins_dir = path / "plugins"
-        if not plugins_dir.exists() or not (plugins_dir / "OptiPatcher.asi").exists():
-            return {"exists": False}
-
-        for variant_id, variant in FSR4_VARIANTS.items():
-            variant_dir = path / variant["dir_name"]
-            variant_path = variant_dir / FSR4_UPSCALER_FILENAME
-            if not variant_path.exists():
-                return {"exists": False}
-            injector = variant.get("injector")
-            if isinstance(injector, dict):
-                if not (variant_dir / injector.get("name", "OptiScaler.dll")).exists():
-                    return {"exists": False}
-                if not (variant_dir / "renames" / "dxgi.dll").exists():
-                    return {"exists": False}
-            for extra_file in variant.get("extra_files", []):
-                if not (variant_dir / extra_file["name"]).exists():
-                    return {"exists": False}
-
-        manifest = self._load_install_manifest(path)
-        selected_variant = self._selected_fsr4_variant(path)
-        return {
-            "exists": True,
-            "version": self._fgmod_version(path),
-            "selected_fsr4_variant": selected_variant,
-            "selected_fsr4_variant_label": FSR4_VARIANTS[selected_variant]["label"],
-            "install_manifest_present": bool(manifest),
-        }
-
-    def _resolve_target_directory(self, directory: str) -> Path:
-        decky.logger.info(f"Resolving target directory: {directory}")
-        target = Path(directory).expanduser()
-        if not target.exists():
-            raise FileNotFoundError(f"Target directory does not exist: {directory}")
-        if not target.is_dir():
-            raise NotADirectoryError(f"Target path is not a directory: {directory}")
-        if not os.access(target, os.W_OK | os.X_OK):
-            raise PermissionError(f"Insufficient permissions for {directory}")
-        decky.logger.info(f"Resolved directory {directory} to absolute path {target}")
-        return target
-
-    def _manual_patch_directory_impl(
-        self,
-        directory: Path,
-        dll_name: str = "dxgi.dll",
-        fsr4_variant: str | None = None,
-        allow_managed_support_cleanup: bool = False,
-    ) -> dict:
-        fgmod_path = Path(decky.HOME) / "fgmod"
-        if not fgmod_path.exists():
-            return {
-                "status": "error",
-                "message": "OptiScaler bundle not installed. Run Install first.",
-            }
-
-        optiscaler_dll = fgmod_path / "OptiScaler.dll"
-        if not optiscaler_dll.exists():
-            return {
-                "status": "error",
-                "message": "OptiScaler.dll not found in ~/fgmod. Reinstall OptiScaler.",
-            }
-
-        preserve_ini = True
-        previous_marker_metadata = self._read_marker(directory / MARKER_FILENAME)
-        previous_variant = str(previous_marker_metadata.get("fsr4_variant") or "").strip()
-        selected_variant = self._selected_fsr4_variant(fgmod_path, fsr4_variant)
-        selected_variant_info = FSR4_VARIANTS[selected_variant]
-        selected_config_overrides = self._fsr4_variant_config_overrides(selected_variant)
-        if previous_variant == "rdna2-valve-411-pre10" and selected_variant != previous_variant:
-            selected_config_overrides.setdefault("FSR.Fsr4ForceModel", "auto")
-            selected_config_overrides.setdefault("Plugins.LoadCustomAmdxc64OnRdna2", "false")
-        selected_upscaler_src = self._fsr4_variant_path(fgmod_path, selected_variant)
-        if not selected_upscaler_src.exists():
-            selected_upscaler_src = fgmod_path / FSR4_UPSCALER_FILENAME
-        if not selected_upscaler_src.exists():
-            return {
-                "status": "error",
-                "message": f"FSR4 upscaler variant not found for {selected_variant}. Reinstall OptiScaler.",
-            }
-        selected_extra_files = self._fsr4_variant_extra_files(selected_variant)
-        optiscaler_version = self._fgmod_version(fgmod_path)
-        selected_upscaler_sha256 = self._file_sha256(selected_upscaler_src)
-
-        try:
-            decky.logger.info(
-                f"Manual patch started for {directory} with FSR4 variant {selected_variant} ({selected_variant_info['label']})"
-            )
-
-            backed_up_proxies = self._backup_preexisting_proxy_files(directory, fgmod_path)
-            decky.logger.info(
-                f"Backed up pre-existing proxy files: {backed_up_proxies}"
-                if backed_up_proxies
-                else "No pre-existing proxy files required backup"
-            )
-
-            removed_patch_files = []
-            for filename in dict.fromkeys(PATCH_CLEANUP_FILES):
-                path = directory / filename
-                if path.exists():
-                    path.unlink()
-                    removed_patch_files.append(filename)
-            decky.logger.info(
-                f"Removed stale patch files: {removed_patch_files}"
-                if removed_patch_files
-                else "No stale patch files found to remove"
-            )
-
-            backed_up_originals = []
-            removed_managed_support = []
-            for dll in ORIGINAL_DLL_BACKUPS:
-                source = directory / dll
-                backup = directory / f"{dll}.b"
-                if not source.exists() or backup.exists():
-                    continue
-                if allow_managed_support_cleanup and self._is_managed_support_file(source, fgmod_path):
-                    source.unlink()
-                    removed_managed_support.append(dll)
-                    continue
-                shutil.move(source, backup)
-                backed_up_originals.append(dll)
-            if removed_managed_support:
-                decky.logger.info(f"Removed managed support files before repatch: {removed_managed_support}")
-            decky.logger.info(
-                f"Backed up original game DLLs: {backed_up_originals}"
-                if backed_up_originals
-                else "No original game DLLs required backup"
-            )
-
-            variant_renamed = self._fsr4_variant_renamed_proxy_path(fgmod_path, selected_variant, dll_name)
-            variant_injector = self._fsr4_variant_injector_path(fgmod_path, selected_variant)
-            root_renamed = fgmod_path / "renames" / dll_name
-            destination_dll = directory / dll_name
-            if variant_renamed and variant_renamed.exists():
-                source_for_copy = variant_renamed
-            elif variant_injector and variant_injector.exists():
-                source_for_copy = variant_injector
-            elif root_renamed.exists():
-                source_for_copy = root_renamed
-            else:
-                source_for_copy = optiscaler_dll
-            shutil.copy2(source_for_copy, destination_dll)
-            decky.logger.info(f"Copied injector DLL from {source_for_copy} to {destination_dll}")
-
-            target_ini = directory / "OptiScaler.ini"
-            source_ini = fgmod_path / "OptiScaler.ini"
-            if preserve_ini and target_ini.exists():
-                decky.logger.info(f"Preserving existing OptiScaler.ini at {target_ini}")
-            elif source_ini.exists():
-                shutil.copy2(source_ini, target_ini)
-                decky.logger.info(f"Copied OptiScaler.ini from {source_ini} to {target_ini}")
-            else:
-                decky.logger.warning("No OptiScaler.ini found to copy")
-
-            if target_ini.exists():
-                self._migrate_optiscaler_ini(target_ini)
-                self._disable_hq_font_auto(target_ini)
-                self._apply_optiscaler_ini_overrides(target_ini, selected_config_overrides)
-
-            plugins_src = fgmod_path / "plugins"
-            plugins_dest = directory / "plugins"
-            if plugins_src.exists():
-                shutil.copytree(plugins_src, plugins_dest, dirs_exist_ok=True)
-                decky.logger.info(f"Synced plugins directory from {plugins_src} to {plugins_dest}")
-            else:
-                decky.logger.warning("Plugins directory missing in fgmod bundle")
-
-            d3d12_src = fgmod_path / "D3D12_Optiscaler"
-            d3d12_dest = directory / "D3D12_Optiscaler"
-            if d3d12_src.exists():
-                shutil.copytree(d3d12_src, d3d12_dest, dirs_exist_ok=True)
-                decky.logger.info(f"Copied D3D12_Optiscaler directory to {d3d12_dest}")
-            else:
-                decky.logger.warning("D3D12_Optiscaler directory missing in fgmod bundle")
-
-            copied_support = []
-            missing_support = []
-            for filename in SUPPORT_FILES:
-                source = fgmod_path / filename
-                dest = directory / filename
-                if source.exists():
-                    shutil.copy2(source, dest)
-                    copied_support.append(filename)
-                else:
-                    missing_support.append(filename)
-
-            upscaler_dest = directory / FSR4_UPSCALER_FILENAME
-            shutil.copy2(selected_upscaler_src, upscaler_dest)
-            copied_support.append(FSR4_UPSCALER_FILENAME)
-
-            for extra_file in selected_extra_files:
-                source = self._fsr4_variant_extra_file_path(fgmod_path, selected_variant, extra_file["name"])
-                dest = directory / extra_file["name"]
-                if source.exists():
-                    shutil.copy2(source, dest)
-                    copied_support.append(extra_file["name"])
-                else:
-                    missing_support.append(extra_file["name"])
-
-            if copied_support:
-                decky.logger.info(f"Copied support files: {copied_support}")
-            if missing_support:
-                decky.logger.warning(f"Support files missing from fgmod bundle: {missing_support}")
-
-            decky.logger.info(f"Manual patch complete for {directory}")
-            return {
-                "status": "success",
-                "message": (
-                    f"OptiScaler files copied to {directory} using "
-                    f"{selected_variant_info['label']}"
-                ),
-                "fsr4_variant": selected_variant,
-                "fsr4_variant_label": selected_variant_info["label"],
-                "fsr4_upscaler_sha256": selected_upscaler_sha256,
-                "optiscaler_version": optiscaler_version,
-            }
-
-        except PermissionError as exc:
-            decky.logger.error(f"Manual patch permission error: {exc}")
-            return {
-                "status": "error",
-                "message": f"Permission error while patching: {exc}",
-            }
-        except Exception as exc:
-            decky.logger.error(f"Manual patch failed: {exc}")
-            return {
-                "status": "error",
-                "message": f"Manual patch failed: {exc}",
-            }
-
-    def _manual_unpatch_directory_impl(self, directory: Path) -> dict:
-        try:
-            decky.logger.info(f"Manual unpatch started for {directory}")
-
-            removed_files = []
-            for filename in set(INJECTOR_FILENAMES + SUPPORT_FILES + VARIANT_EXTRA_FILENAMES + [FSR4_UPSCALER_FILENAME]):
-                path = directory / filename
-                if path.exists():
-                    path.unlink()
-                    removed_files.append(filename)
-            decky.logger.info(f"Removed injector/support files: {removed_files}" if removed_files else "No injector/support files found to remove")
-
-            legacy_removed = []
-            for legacy in LEGACY_FILES:
-                path = directory / legacy
-                if path.exists():
-                    try:
-                        path.unlink()
-                    except IsADirectoryError:
-                        shutil.rmtree(path, ignore_errors=True)
-                    legacy_removed.append(legacy)
-            decky.logger.info(f"Removed legacy artifacts: {legacy_removed}" if legacy_removed else "No legacy artifacts present")
-
-            plugins_dir = directory / "plugins"
-            if plugins_dir.exists():
-                shutil.rmtree(plugins_dir, ignore_errors=True)
-                decky.logger.info(f"Removed plugins directory at {plugins_dir}")
-
-            d3d12_dir = directory / "D3D12_Optiscaler"
-            if d3d12_dir.exists():
-                shutil.rmtree(d3d12_dir, ignore_errors=True)
-                decky.logger.info(f"Removed D3D12_Optiscaler directory from {d3d12_dir}")
-
-            restored_backups = []
-            for dll in dict.fromkeys(RESTORABLE_BACKUP_FILES):
-                backup = directory / f"{dll}.b"
-                original = directory / dll
-                if backup.exists():
-                    if original.exists():
-                        original.unlink()
-                    shutil.move(backup, original)
-                    restored_backups.append(dll)
-            decky.logger.info(f"Restored backups: {restored_backups}" if restored_backups else "No backups found to restore")
-
-            uninstaller = directory / "fgmod-uninstaller.sh"
-            if uninstaller.exists():
-                uninstaller.unlink()
-                decky.logger.info(f"Removed fgmod uninstaller at {uninstaller}")
-
-            decky.logger.info(f"Manual unpatch complete for {directory}")
-            return {
-                "status": "success",
-                "message": f"OptiScaler files removed from {directory}",
-            }
-
-        except PermissionError as exc:
-            decky.logger.error(f"Manual unpatch permission error: {exc}")
-            return {
-                "status": "error",
-                "message": f"Permission error while unpatching: {exc}",
-            }
-        except Exception as exc:
-            decky.logger.error(f"Manual unpatch failed: {exc}")
-            return {
-                "status": "error",
-                "message": f"Manual unpatch failed: {exc}",
-            }
-
-    # ── Steam library discovery ───────────────────────────────────────────────
-
-    def _home_path(self) -> Path:
-        try:
-            return Path(decky.HOME)
-        except TypeError:
-            return Path(str(decky.HOME))
-
-    def _steam_root_candidates(self) -> list[Path]:
-        home = self._home_path()
-        candidates = [
-            home / ".local" / "share" / "Steam",
-            home / ".steam" / "steam",
-            home / ".steam" / "root",
-            home / ".var" / "app" / "com.valvesoftware.Steam" / "home" / ".local" / "share" / "Steam",
-            home / ".var" / "app" / "com.valvesoftware.Steam" / "home" / ".steam" / "steam",
-        ]
-        unique: list[Path] = []
-        seen: set[str] = set()
-        for c in candidates:
-            key = str(c)
-            if key not in seen:
-                unique.append(c)
-                seen.add(key)
-        return unique
-
-    def _steam_library_paths(self) -> list[Path]:
-        library_paths: list[Path] = []
-        seen: set[str] = set()
-        for steam_root in self._steam_root_candidates():
-            if steam_root.exists():
-                key = str(steam_root)
-                if key not in seen:
-                    library_paths.append(steam_root)
-                    seen.add(key)
-            library_file = steam_root / "steamapps" / "libraryfolders.vdf"
-            if not library_file.exists():
-                continue
-            try:
-                with open(library_file, "r", encoding="utf-8", errors="replace") as f:
-                    for line in f:
-                        if '"path"' not in line:
-                            continue
-                        path = line.split('"path"', 1)[1].strip().strip('"').replace("\\\\", "/")
-                        candidate = Path(path)
-                        key = str(candidate)
-                        if key not in seen:
-                            library_paths.append(candidate)
-                            seen.add(key)
-            except Exception as exc:
-                decky.logger.error(f"[Framegen] failed to parse libraryfolders: {library_file}: {exc}")
-        return library_paths
-
-    def _find_installed_games(self, appid: str | None = None) -> list[dict]:
-        games: list[dict] = []
-        for library_path in self._steam_library_paths():
-            steamapps_path = library_path / "steamapps"
-            if not steamapps_path.exists():
-                continue
-            for appmanifest in steamapps_path.glob("appmanifest_*.acf"):
-                game_info: dict = {"appid": "", "name": "", "library_path": str(library_path), "install_path": ""}
-                install_dir = ""
-                try:
-                    with open(appmanifest, "r", encoding="utf-8", errors="replace") as f:
-                        for line in f:
-                            if '"appid"' in line:
-                                game_info["appid"] = line.split('"appid"', 1)[1].strip().strip('"')
-                            elif '"name"' in line:
-                                game_info["name"] = line.split('"name"', 1)[1].strip().strip('"')
-                            elif '"installdir"' in line:
-                                install_dir = line.split('"installdir"', 1)[1].strip().strip('"')
-                except Exception as exc:
-                    decky.logger.error(f"[Framegen] skipping manifest {appmanifest}: {exc}")
-                    continue
-                if not game_info["appid"] or not game_info["name"]:
-                    continue
-                if "Proton" in game_info["name"] or "Steam Linux Runtime" in game_info["name"]:
-                    continue
-                install_path = steamapps_path / "common" / install_dir if install_dir else Path()
-                game_info["install_path"] = str(install_path)
-                if appid is None or str(game_info["appid"]) == str(appid):
-                    games.append(game_info)
-        deduped: dict[str, dict] = {}
-        for game in games:
-            deduped[str(game["appid"])] = game
-        return sorted(deduped.values(), key=lambda g: g["name"].lower())
-
-    def _game_record(self, appid: str) -> dict | None:
-        matches = self._find_installed_games(appid)
-        return matches[0] if matches else None
-
-    # ── Patch target auto-detection ───────────────────────────────────────────
-
-    def _normalized_path_string(self, value: str) -> str:
-        normalized = value.lower().replace("\\", "/")
-        normalized = normalized.replace("z:/", "/")
-        normalized = normalized.replace("//", "/")
-        return normalized
-
-    def _candidate_executables(self, install_root: Path) -> list[Path]:
-        if not install_root.exists():
-            return []
-        candidates: list[Path] = []
-        try:
-            for exe in install_root.rglob("*.exe"):
-                if exe.is_file():
-                    candidates.append(exe)
-        except Exception as exc:
-            decky.logger.error(f"[Framegen] exe scan failed for {install_root}: {exc}")
-        return candidates
-
-    def _exe_score(self, exe: Path, install_root: Path, game_name: str) -> int:
-        normalized = self._normalized_path_string(str(exe))
-        name = exe.name.lower()
-        score = 0
-        if normalized.endswith("-win64-shipping.exe"):
-            score += 300
-        if "shipping.exe" in name:
-            score += 220
-        if "/binaries/win64/" in normalized:
-            score += 200
-        if "/win64/" in normalized:
-            score += 80
-        if exe.parent == install_root:
-            score += 20
-        sanitized_game = re.sub(r"[^a-z0-9]", "", game_name.lower())
-        sanitized_name = re.sub(r"[^a-z0-9]", "", exe.stem.lower())
-        sanitized_root = re.sub(r"[^a-z0-9]", "", install_root.name.lower())
-        if sanitized_game and sanitized_game in sanitized_name:
-            score += 120
-        if sanitized_root and sanitized_root in sanitized_name:
-            score += 90
-        for bad in BAD_EXE_SUBSTRINGS:
-            if bad in normalized:
-                score -= 200
-        score -= len(exe.parts)
-        return score
-
-    def _best_running_executable(self, candidates: list[Path]) -> Path | None:
-        if not candidates:
-            return None
-        try:
-            result = subprocess.run(["ps", "-eo", "args="], capture_output=True, text=True, check=False)
-            process_lines = result.stdout.splitlines()
-        except Exception as exc:
-            decky.logger.error(f"[Framegen] running exe scan failed: {exc}")
-            return None
-        normalized_candidates = [(exe, self._normalized_path_string(str(exe))) for exe in candidates]
-        matches: list[tuple[int, Path]] = []
-        for line in process_lines:
-            normalized_line = self._normalized_path_string(line)
-            for exe, normalized_exe in normalized_candidates:
-                if normalized_exe in normalized_line:
-                    matches.append((len(normalized_exe), exe))
-        if not matches:
-            return None
-        matches.sort(key=lambda item: item[0], reverse=True)
-        return matches[0][1]
-
-    def _guess_patch_target(self, game_info: dict) -> tuple[Path, Path | None]:
-        install_root = Path(game_info["install_path"])
-        candidates = self._candidate_executables(install_root)
-        if not candidates:
-            return install_root, None
-        running_exe = self._best_running_executable(candidates)
-        if running_exe:
-            return running_exe.parent, running_exe
-        best = max(candidates, key=lambda exe: self._exe_score(exe, install_root, game_info["name"]))
-        return best.parent, best
-
-    def _is_game_running(self, game_info: dict) -> bool:
-        install_root = Path(game_info["install_path"])
-        candidates = self._candidate_executables(install_root)
-        return self._best_running_executable(candidates) is not None
-
-    # ── Marker file tracking ──────────────────────────────────────────────────
-
-    def _find_marker(self, install_root: Path) -> Path | None:
-        if not install_root.exists():
-            return None
-        try:
-            for marker in install_root.rglob(MARKER_FILENAME):
-                if marker.is_file():
-                    return marker
-        except Exception:
-            pass
-        return None
-
-    def _read_marker(self, marker_path: Path) -> dict:
-        try:
-            with open(marker_path, "r", encoding="utf-8") as f:
-                data = json.load(f)
-            return data if isinstance(data, dict) else {}
-        except Exception:
-            return {}
-
-    def _write_marker(
-        self,
-        marker_path: Path,
-        *,
-        appid: str,
-        game_name: str,
-        dll_name: str,
-        target_dir: Path,
-        original_launch_options: str,
-        backed_up_files: list[str],
-        optiscaler_version: str | None = None,
-        fsr4_variant: str | None = None,
-        fsr4_upscaler_sha256: str | None = None,
-    ) -> None:
-        normalized_variant = self._normalize_fsr4_variant(fsr4_variant)
-        variant_info = FSR4_VARIANTS[normalized_variant]
-        payload = {
-            "appid": str(appid),
-            "game_name": game_name,
-            "dll_name": dll_name,
-            "target_dir": str(target_dir),
-            "original_launch_options": original_launch_options,
-            "backed_up_files": backed_up_files,
-            "optiscaler_version": optiscaler_version,
-            "fsr4_variant": normalized_variant,
-            "fsr4_variant_label": variant_info["label"],
-            "fsr4_upscaler_sha256": fsr4_upscaler_sha256,
-            "managed_files": [
-                {
-                    "path": str(target_dir / FSR4_UPSCALER_FILENAME),
-                    "sha256": fsr4_upscaler_sha256,
-                    "kind": "fsr4-upscaler",
-                    "variant": normalized_variant,
-                }
-            ],
-            "patched_at": datetime.now(timezone.utc).isoformat(),
-        }
-        self._write_json_file(marker_path, payload)
-
-    # ── Launch options helpers ────────────────────────────────────────────────
-
-    def _build_managed_launch_options(self, dll_name: str) -> str:
-        if dll_name == "OptiScaler.asi":
-            return "SteamDeck=0 %command%"
-        base = dll_name.replace(".dll", "")
-        return f"WINEDLLOVERRIDES={base}=n,b SteamDeck=0 %command%"
-
-    def _is_managed_launch_options(self, opts: str) -> bool:
-        if not opts or not opts.strip():
-            return False
-        normalized = " ".join(opts.strip().split())
-        for dll_name in VALID_DLL_NAMES:
-            if dll_name == "OptiScaler.asi":
-                continue
-            base = dll_name.replace(".dll", "")
-            if f"WINEDLLOVERRIDES={base}=n,b" in normalized:
-                return True
-        if "fgmod/fgmod" in normalized:
-            return True
-        return False
+        return self._bundle.check()
 
     async def list_installed_games(self) -> dict:
-        try:
-            games = []
-            for game in self._find_installed_games():
-                install_root = Path(game["install_path"])
-                games.append({
-                    "appid": str(game["appid"]),
-                    "name": game["name"],
-                    "install_found": install_root.exists(),
-                })
-            return {"status": "success", "games": games}
-        except Exception as e:
-            decky.logger.error(str(e))
-            return {"status": "error", "message": str(e)}
+        return self._patcher.list_installed_games()
 
     async def get_path_defaults(self) -> dict:
-        try:
-            home_path = Path(decky.HOME)
-        except TypeError:
-            home_path = Path(str(decky.HOME))
-
-        steam_common = home_path / ".local" / "share" / "Steam" / "steamapps" / "common"
-
-        return {
-            "home": str(home_path),
-            "steam_common": str(steam_common),
-        }
+        return {"home": str(self._steam.home), "steam_common": str(self._steam.steam_common_path())}
 
     async def log_error(self, error: str) -> None:
         decky.logger.error(f"FRONTEND: {error}")
@@ -1667,109 +69,15 @@ class Plugin:
         directory: str,
         dll_name: str = "dxgi.dll",
         fsr4_variant: str = DEFAULT_FSR4_VARIANT,
+        framegen_backend: str = DEFAULT_FRAMEGEN_BACKEND,
     ) -> dict:
-        if dll_name not in VALID_DLL_NAMES:
-            return {"status": "error", "message": f"Invalid proxy DLL name: {dll_name}"}
-        try:
-            target_dir = self._resolve_target_directory(directory)
-        except (FileNotFoundError, NotADirectoryError, PermissionError) as exc:
-            decky.logger.error(f"Manual patch validation failed: {exc}")
-            return {"status": "error", "message": str(exc)}
-
-        allow_managed_support_cleanup = (target_dir / MARKER_FILENAME).exists()
-        return self._manual_patch_directory_impl(
-            target_dir,
-            dll_name,
-            fsr4_variant,
-            allow_managed_support_cleanup=allow_managed_support_cleanup,
-        )
+        return self._patcher.manual_patch_directory(directory, dll_name, fsr4_variant, framegen_backend)
 
     async def manual_unpatch_directory(self, directory: str) -> dict:
-        try:
-            target_dir = self._resolve_target_directory(directory)
-        except (FileNotFoundError, NotADirectoryError, PermissionError) as exc:
-            decky.logger.error(f"Manual unpatch validation failed: {exc}")
-            return {"status": "error", "message": str(exc)}
-
-        return self._manual_unpatch_directory_impl(target_dir)
-
-    # ── AppID-based patch / unpatch / status ───────────────────────────────────────
+        return self._patcher.manual_unpatch_directory(directory)
 
     async def get_game_status(self, appid: str) -> dict:
-        try:
-            game_info = self._game_record(str(appid))
-            if not game_info:
-                return {
-                    "status": "success",
-                    "appid": str(appid),
-                    "install_found": False,
-                    "patched": False,
-                    "dll_name": None,
-                    "target_dir": None,
-                    "fsr4_variant": None,
-                    "fsr4_variant_label": None,
-                    "message": "Game not found in Steam library.",
-                }
-            install_root = Path(game_info["install_path"])
-            if not install_root.exists():
-                return {
-                    "status": "success",
-                    "appid": str(appid),
-                    "name": game_info["name"],
-                    "install_found": False,
-                    "patched": False,
-                    "dll_name": None,
-                    "target_dir": None,
-                    "fsr4_variant": None,
-                    "fsr4_variant_label": None,
-                    "message": "Game install directory not found.",
-                }
-            marker = self._find_marker(install_root)
-            if not marker:
-                return {
-                    "status": "success",
-                    "appid": str(appid),
-                    "name": game_info["name"],
-                    "install_found": True,
-                    "patched": False,
-                    "dll_name": None,
-                    "target_dir": None,
-                    "fsr4_variant": None,
-                    "fsr4_variant_label": None,
-                    "message": "Not patched.",
-                }
-            metadata = self._read_marker(marker)
-            dll_name = metadata.get("dll_name", "dxgi.dll")
-            target_dir = Path(metadata.get("target_dir", str(marker.parent)))
-            dll_present = (target_dir / dll_name).exists()
-            upscaler_path = target_dir / FSR4_UPSCALER_FILENAME
-            upscaler_sha256 = self._file_sha256(upscaler_path) if upscaler_path.exists() else None
-            detected_variant = self._detect_fsr4_variant(target_dir, upscaler_sha256)
-            stored_variant = str(metadata.get("fsr4_variant") or "").strip() or None
-            effective_variant = detected_variant or (stored_variant if stored_variant in FSR4_VARIANTS else None)
-            effective_label = FSR4_VARIANTS[effective_variant]["label"] if effective_variant else None
-            return {
-                "status": "success",
-                "appid": str(appid),
-                "name": game_info["name"],
-                "install_found": True,
-                "patched": dll_present,
-                "dll_name": dll_name,
-                "target_dir": str(target_dir),
-                "patched_at": metadata.get("patched_at"),
-                "optiscaler_version": metadata.get("optiscaler_version"),
-                "fsr4_variant": effective_variant,
-                "fsr4_variant_label": effective_label,
-                "fsr4_upscaler_sha256": upscaler_sha256,
-                "message": (
-                    f"Patched using {dll_name}" + (f" with {effective_label}." if effective_label else ".")
-                    if dll_present
-                    else f"Marker found but {dll_name} is missing. Reinstall recommended."
-                ),
-            }
-        except Exception as exc:
-            decky.logger.error(f"[Framegen] get_game_status failed for {appid}: {exc}")
-            return {"status": "error", "message": str(exc)}
+        return self._patcher.get_game_status(appid)
 
     async def patch_game(
         self,
@@ -1777,137 +85,9 @@ class Plugin:
         dll_name: str = "dxgi.dll",
         current_launch_options: str = "",
         fsr4_variant: str = DEFAULT_FSR4_VARIANT,
+        framegen_backend: str = DEFAULT_FRAMEGEN_BACKEND,
     ) -> dict:
-        try:
-            if dll_name not in VALID_DLL_NAMES:
-                return {"status": "error", "message": f"Invalid proxy DLL name: {dll_name}"}
-            game_info = self._game_record(str(appid))
-            if not game_info:
-                return {"status": "error", "message": "Game not found in Steam library."}
-            install_root = Path(game_info["install_path"])
-            if not install_root.exists():
-                return {"status": "error", "message": "Game install directory does not exist."}
-            if self._is_game_running(game_info):
-                return {"status": "error", "message": "Close the game before patching."}
-            fgmod_path = Path(decky.HOME) / "fgmod"
-            if not fgmod_path.exists():
-                return {"status": "error", "message": "OptiScaler bundle not installed. Run Install first."}
-
-            # Preserve true original launch options across re-patches
-            original_launch_options = current_launch_options or ""
-            existing_marker = self._find_marker(install_root)
-            existing_marker_metadata = self._read_marker(existing_marker) if existing_marker else {}
-            existing_marker_target_dir = Path(
-                existing_marker_metadata.get("target_dir", str(existing_marker.parent))
-            ) if existing_marker else None
-            if existing_marker:
-                stored_opts = str(existing_marker_metadata.get("original_launch_options") or "")
-                if stored_opts and not self._is_managed_launch_options(stored_opts):
-                    original_launch_options = stored_opts
-            if self._is_managed_launch_options(original_launch_options):
-                original_launch_options = ""
-
-            # Auto-detect the right directory to patch
-            target_dir, target_exe = self._guess_patch_target(game_info)
-            decky.logger.info(f"[Framegen] patch_game: appid={appid} dll={dll_name} target={target_dir} exe={target_exe}")
-
-            allow_managed_support_cleanup = bool(
-                existing_marker and existing_marker_target_dir == target_dir
-            ) or (target_dir / MARKER_FILENAME).exists()
-            result = self._manual_patch_directory_impl(
-                target_dir,
-                dll_name,
-                fsr4_variant,
-                allow_managed_support_cleanup=allow_managed_support_cleanup,
-            )
-            if result["status"] != "success":
-                return result
-
-            backed_up = [dll for dll in dict.fromkeys(RESTORABLE_BACKUP_FILES) if (target_dir / f"{dll}.b").exists()]
-            marker_path = target_dir / MARKER_FILENAME
-            self._write_marker(
-                marker_path,
-                appid=str(appid),
-                game_name=game_info["name"],
-                dll_name=dll_name,
-                target_dir=target_dir,
-                original_launch_options=original_launch_options,
-                backed_up_files=backed_up,
-                optiscaler_version=result.get("optiscaler_version"),
-                fsr4_variant=result.get("fsr4_variant"),
-                fsr4_upscaler_sha256=result.get("fsr4_upscaler_sha256"),
-            )
-
-            if existing_marker and existing_marker != marker_path:
-                try:
-                    existing_marker.unlink()
-                except Exception:
-                    pass
-
-            managed_launch_options = self._build_managed_launch_options(dll_name)
-            decky.logger.info(f"[Framegen] patch_game success: appid={appid} launch_options={managed_launch_options}")
-            return {
-                "status": "success",
-                "appid": str(appid),
-                "name": game_info["name"],
-                "dll_name": dll_name,
-                "target_dir": str(target_dir),
-                "launch_options": managed_launch_options,
-                "original_launch_options": original_launch_options,
-                "optiscaler_version": result.get("optiscaler_version"),
-                "fsr4_variant": result.get("fsr4_variant"),
-                "fsr4_variant_label": result.get("fsr4_variant_label"),
-                "fsr4_upscaler_sha256": result.get("fsr4_upscaler_sha256"),
-                "message": (
-                    f"Patched {game_info['name']} using {dll_name} "
-                    f"with {result.get('fsr4_variant_label', FSR4_VARIANTS[self._normalize_fsr4_variant(fsr4_variant)]['label'])}."
-                ),
-            }
-        except Exception as exc:
-            decky.logger.error(f"[Framegen] patch_game failed for {appid}: {exc}")
-            return {"status": "error", "message": str(exc)}
+        return self._patcher.patch_game(appid, dll_name, current_launch_options, fsr4_variant, framegen_backend)
 
     async def unpatch_game(self, appid: str) -> dict:
-        try:
-            game_info = self._game_record(str(appid))
-            if not game_info:
-                return {"status": "error", "message": "Game not found in Steam library."}
-            install_root = Path(game_info["install_path"])
-            if not install_root.exists():
-                return {
-                    "status": "success",
-                    "appid": str(appid),
-                    "name": game_info["name"],
-                    "launch_options": "",
-                    "message": "Game install directory does not exist.",
-                }
-            if self._is_game_running(game_info):
-                return {"status": "error", "message": "Close the game before unpatching."}
-            marker = self._find_marker(install_root)
-            if not marker:
-                return {
-                    "status": "success",
-                    "appid": str(appid),
-                    "name": game_info["name"],
-                    "launch_options": "",
-                    "message": "No Framegen patch found for this game.",
-                }
-            metadata = self._read_marker(marker)
-            target_dir = Path(metadata.get("target_dir", str(marker.parent)))
-            original_launch_options = str(metadata.get("original_launch_options") or "")
-            self._manual_unpatch_directory_impl(target_dir)
-            try:
-                marker.unlink()
-            except FileNotFoundError:
-                pass
-            decky.logger.info(f"[Framegen] unpatch_game success: appid={appid} target={target_dir}")
-            return {
-                "status": "success",
-                "appid": str(appid),
-                "name": game_info["name"],
-                "launch_options": original_launch_options,
-                "message": f"Unpatched {game_info['name']}.",
-            }
-        except Exception as exc:
-            decky.logger.error(f"[Framegen] unpatch_game failed for {appid}: {exc}")
-            return {"status": "error", "message": str(exc)}
+        return self._patcher.unpatch_game(appid)