feat: proxy DLL name picker

Expose the proxy DLL rename as a user-selectable option across all
injection paths.  Previously hardcoded to dxgi.dll with no way to
change it short of manually prepending DLL=<name> to the Steam launch
option.

src/utils/constants.ts
- Add PROXY_DLL_OPTIONS (7 entries matching _create_renamed_copies)
  each with a label and one-line hint
- Add DEFAULT_PROXY_DLL constant (dxgi.dll) and ProxyDllValue type

src/api/index.ts
- runManualPatch now takes [directory, dll_name] so the chosen name
  reaches the backend

src/components/OptiScalerControls.tsx
- Own dllName state (default: dxgi.dll)
- Render a DropdownItem (visible when installed) showing the 7 options
  with the selected option's hint as the description
- Pass dllName down to both ClipboardCommands and ManualPatchControls

src/components/ClipboardCommands.tsx
- Accept dllName prop
- Patch command is plain ~/fgmod/fgmod %command% for the default;
  prefixed DLL=<name> ~/fgmod/fgmod %command% for any other choice

src/components/CustomPathOverride.tsx
- Accept dllName prop
- Pass it to runManualPatch
- Manual launch cmd clipboard button builds
  WINEDLLOVERRIDES="<stem>=n,b" dynamically; emits bare
  SteamDeck=0 %command% for OptiScaler.asi (ASI loader path needs no
  Wine DLL override)

main.py
- Add VALID_DLL_NAMES set (whitelist matching the renames dir)
- manual_patch_directory validates dll_name against the whitelist and
  returns an error for unknown values
- _manual_patch_directory_impl accepts dll_name param; removes the
  hardcoded "dxgi.dll" line

defaults/assets/fgmod.sh
- Fix longstanding bug: WINEDLLOVERRIDES was hardcoded to dxgi=n,b
  regardless of the DLL= env var selection.  Now derives the stem from
  $dll_name and skips the override entirely for .asi files.

3 files changed, 40 insertions, 13 deletions

diff --git a/src/components/ClipboardCommands.tsx b/src/components/ClipboardCommands.tsx
index 5a6f38f..b8cf6bf 100644
--- a/src/components/ClipboardCommands.tsx
+++ b/src/components/ClipboardCommands.tsx
@@ -1,20 +1,27 @@
 import { SmartClipboardButton } from "./SmartClipboardButton";
+import { DEFAULT_PROXY_DLL } from "../utils/constants";
 
 interface ClipboardCommandsProps {
   pathExists: boolean | null;
+  dllName: string;
 }
 
-export function ClipboardCommands({ pathExists }: ClipboardCommandsProps) {
+export function ClipboardCommands({ pathExists, dllName }: ClipboardCommandsProps) {
   if (pathExists !== true) return null;
 
+  const launchCommand =
+    dllName === DEFAULT_PROXY_DLL
+      ? "~/fgmod/fgmod %command%"
+      : `DLL=${dllName} ~/fgmod/fgmod %command%`;
+
   return (
     <>
-      <SmartClipboardButton 
-        command="~/fgmod/fgmod %command%"
+      <SmartClipboardButton
+        command={launchCommand}
         buttonText="Copy Patch Command"
       />
-      
-      <SmartClipboardButton 
+
+      <SmartClipboardButton
         command="~/fgmod/fgmod-uninstaller.sh %command%"
         buttonText="Copy Unpatch Command"
       />
diff --git a/src/components/CustomPathOverride.tsx b/src/components/CustomPathOverride.tsx
index ffc4b1f..14a0905 100644
--- a/src/components/CustomPathOverride.tsx
+++ b/src/components/CustomPathOverride.tsx
@@ -36,6 +36,7 @@ const ensureDirectory = (value: string) => {
 interface ManualPatchControlsProps {
   isAvailable: boolean;
   onManualModeChange?: (enabled: boolean) => void;
+  dllName: string;
 }
 
 interface PickerState {
@@ -56,7 +57,7 @@ const formatResultMessage = (result: ApiResponse | null) => {
   return result.message || result.output || "Operation failed.";
 };
 
-export const ManualPatchControls = ({ isAvailable, onManualModeChange }: ManualPatchControlsProps) => {
+export const ManualPatchControls = ({ isAvailable, onManualModeChange, dllName }: ManualPatchControlsProps) => {
   const [isEnabled, setEnabled] = useState(false);
   const [defaults, setDefaults] = useState<PathDefaults>(INITIAL_DEFAULTS);
   const [pickerState, setPickerState] = useState<PickerState>(INITIAL_PICKER_STATE);
@@ -165,7 +166,7 @@ export const ManualPatchControls = ({ isAvailable, onManualModeChange }: ManualP
       try {
         const response =
           action === "patch"
-            ? await runManualPatch(selectedPath)
+            ? await runManualPatch(selectedPath, dllName)
             : await runManualUnpatch(selectedPath);
         setOperationResult(response ?? { status: "error", message: "No response from backend." });
       } catch (err) {
@@ -177,7 +178,7 @@ export const ManualPatchControls = ({ isAvailable, onManualModeChange }: ManualP
         setBusy(false);
       }
     },
-    [selectedPath]
+    [selectedPath, dllName]
   );
 
   const handleToggle = (value: boolean) => {
@@ -216,7 +217,11 @@ export const ManualPatchControls = ({ isAvailable, onManualModeChange }: ManualP
       {canInteract && (
         <>
           <SmartClipboardButton
-            command='WINEDLLOVERRIDES="dxgi=n,b" SteamDeck=0 %command%'
+            command={
+              dllName === "OptiScaler.asi"
+                ? "SteamDeck=0 %command%"
+                : `WINEDLLOVERRIDES="${dllName.replace(".dll", "")}=n,b" SteamDeck=0 %command%`
+            }
             buttonText="Manual launch cmd"
           />
           <PanelSectionRow>
diff --git a/src/components/OptiScalerControls.tsx b/src/components/OptiScalerControls.tsx
index 468683c..fb5d2f8 100644
--- a/src/components/OptiScalerControls.tsx
+++ b/src/components/OptiScalerControls.tsx
@@ -1,9 +1,9 @@
 import { useState, useEffect } from "react";
-import { PanelSection } from "@decky/ui";
+import { DropdownItem, PanelSection, PanelSectionRow } from "@decky/ui";
 import { runInstallFGMod, runUninstallFGMod } from "../api";
 import { OperationResult } from "./ResultDisplay";
 import { createAutoCleanupTimer } from "../utils";
-import { TIMEOUTS } from "../utils/constants";
+import { TIMEOUTS, PROXY_DLL_OPTIONS, DEFAULT_PROXY_DLL } from "../utils/constants";
 import { InstallationStatus } from "./InstallationStatus";
 import { OptiScalerHeader } from "./OptiScalerHeader";
 import { ClipboardCommands } from "./ClipboardCommands";
@@ -23,6 +23,7 @@ export function OptiScalerControls({ pathExists, setPathExists }: OptiScalerCont
   const [installResult, setInstallResult] = useState<OperationResult | null>(null);
   const [uninstallResult, setUninstallResult] = useState<OperationResult | null>(null);
   const [manualModeEnabled, setManualModeEnabled] = useState(false);
+  const [dllName, setDllName] = useState<string>(DEFAULT_PROXY_DLL);
   useEffect(() => {
     if (installResult) {
       return createAutoCleanupTimer(() => setInstallResult(null), TIMEOUTS.resultDisplay);
@@ -76,15 +77,29 @@ export function OptiScalerControls({ pathExists, setPathExists }: OptiScalerCont
       />
       
       <OptiScalerHeader pathExists={pathExists} />
-      
+
+      {pathExists === true && (
+        <PanelSectionRow>
+          <DropdownItem
+            label="Proxy DLL name"
+            description={PROXY_DLL_OPTIONS.find((o) => o.value === dllName)?.hint}
+            menuLabel="Proxy DLL name"
+            selectedOption={dllName}
+            rgOptions={PROXY_DLL_OPTIONS.map((o) => ({ data: o.value, label: o.label }))}
+            onChange={(option) => setDllName(String(option.data))}
+          />
+        </PanelSectionRow>
+      )}
+
       <ManualPatchControls
         isAvailable={pathExists === true}
         onManualModeChange={setManualModeEnabled}
+        dllName={dllName}
       />
 
       {!manualModeEnabled && (
         <>
-          <ClipboardCommands pathExists={pathExists} />
+          <ClipboardCommands pathExists={pathExists} dllName={dllName} />
           
           <InstructionCard pathExists={pathExists} />
         </>