feat(sync-ui): sync window self-spawns the app, dropping the local launcher/bun requirement

resolveSyncLauncherCommand now returns process.execPath + --sync-cli
(with the app path prepended in dev runs) instead of hunting for bun and
the bundled launcher script. Same NDJSON child protocol, so the sync
window, checks, and auto-sync scheduler are unchanged.

src/main.ts

@@ -2257,7 +2257,11 @@ const syncUiRuntime = createSyncUiRuntime({
     const configured = getResolvedConfig().immersionTracking?.dbPath?.trim();
     return configured || DEFAULT_IMMERSION_DB_PATH;
   },
-  resolveLauncherCommand: () => resolveSyncLauncherCommand(),
+  resolveLauncherCommand: () =>
+    resolveSyncLauncherCommand({
+      execPath: process.execPath,
+      appPath: app.isPackaged ? null : app.getAppPath(),
+    }),
   runLauncher: runSyncLauncher,
   getWindow: () => appState.syncUiWindow,
   pickSnapshotFile: async () => {