fix(desktop): preserve startMinimized preference across off/on cycle on Windows

When autostart is disabled, Windows deletes the Run registry entry, so
deriveStartMinimizedFromArgs(undefined) was returning false and silently
resetting the user's startMinimized preference the next time autostart
was re-enabled. Both the get- and set-auto-launch-settings handlers now
fall back to the disk-cached value when no OS entry exists, matching the
existing macOS/Linux fallback pattern.

packages/desktop/src/main.ts

@@ -558,9 +558,16 @@ function registerIpcHandlers(): void {
       const ownEntry = osState.launchItems?.find(
         (item) => item.name === 'Backspace' || item.path?.toLowerCase() === process.execPath.toLowerCase(),
       );
+      // When the Run entry exists, its args are the source of truth for startMinimized.
+      // When the entry is absent (autostart is off), there is no OS state to read, so we
+      // fall back to the disk cache — this preserves the user's preference across an
+      // off/on cycle so re-enabling restores their previous startMinimized choice.
+      const startMinimized = ownEntry
+        ? deriveStartMinimizedFromArgs(ownEntry.args)
+        : loadAutoLaunchSettings().startMinimized;
       return {
         openAtLogin: osState.executableWillLaunchAtLogin ?? false,
-        startMinimized: deriveStartMinimizedFromArgs(ownEntry?.args),
+        startMinimized,
       };
     }
     // macOS and Linux: getLoginItemSettings doesn't expose args, so startMinimized
@@ -587,7 +594,12 @@ function registerIpcHandlers(): void {
         (item) => item.name === 'Backspace' || item.path?.toLowerCase() === process.execPath.toLowerCase(),
       );
       currentOpenAtLogin = osState.executableWillLaunchAtLogin ?? false;
-      currentStartMinimized = deriveStartMinimizedFromArgs(ownEntry?.args);
+      // See `get-auto-launch-settings`: when the entry is absent, fall back to disk
+      // cache so a partial update that re-enables openAtLogin restores the user's
+      // previously-saved startMinimized choice rather than resetting to false.
+      currentStartMinimized = ownEntry
+        ? deriveStartMinimizedFromArgs(ownEntry.args)
+        : loadAutoLaunchSettings().startMinimized;
     } else {
       const osState = app.getLoginItemSettings();
       const saved = loadAutoLaunchSettings();