fix(electrobun): native folder picker via zenity — proper dark theme + folder mode

- Uses zenity --file-selection --directory for proper GTK folder chooser
  (correct "Select Project Folder" title, dirs sorted first, dark theme)
- Falls back to Electrobun Utils.openFileDialog if zenity unavailable
- RPC timeout increased to 120s (native dialogs block until user closes)
- zenity respects system GTK theme + color-scheme prefer-dark

ui-electrobun/src/bun/index.ts

@@ -105,7 +105,7 @@ const gitHandlers = createGitHandlers();
 // ── RPC definition ─────────────────────────────────────────────────────────
 
 const rpc = BrowserView.defineRPC<PtyRPCSchema>({
-  maxRequestTime: 15_000,
+  maxRequestTime: 120_000, // 2 min — native dialogs block until user closes
   handlers: {
     requests: {
       // PTY
@@ -128,8 +128,20 @@ const rpc = BrowserView.defineRPC<PtyRPCSchema>({
       // Git
       ...gitHandlers,
 
-      // Native folder picker dialog
+      // Native folder picker dialog via zenity (proper GTK folder chooser)
       "files.pickDirectory": async ({ startingFolder }) => {
+        try {
+          const { execSync } = await import("child_process");
+          const start = startingFolder?.replace(/^~/, process.env.HOME || "/home") || process.env.HOME || "/home";
+          // zenity --file-selection --directory gives a proper "Select Folder" dialog
+          // with dark theme support, dirs sorted first, and correct title
+          const result = execSync(
+            `zenity --file-selection --directory --title="Select Project Folder" --filename="${start}/"`,
+            { encoding: "utf-8", timeout: 120_000 }
+          ).trim();
+          return { path: result || null };
+        } catch {
+          // User cancelled or zenity not found — try Electrobun fallback
           try {
             const paths = await Utils.openFileDialog({
               startingFolder: startingFolder || "~/",
@@ -139,6 +151,7 @@ const rpc = BrowserView.defineRPC<PtyRPCSchema>({
             });
             return { path: paths?.[0] ?? null };
           } catch { return { path: null }; }
+        }
       },
 
       // Home directory