feat: Google's gemini-cli integration (#422)

* feat: integrate Gemini AI agent provider

- Core Backend: Ported gemini-cli.js and gemini-response-handler.js to establish the CLI bridge. Registered 'gemini' as an active provider within index.js.
- Core Frontend: Extended QuickSettingsPanel.jsx, Settings.jsx, and AgentListItem.jsx to render the Gemini provider option, models (gemini-pro, gemini-flash, etc.), and handle OAuth states.
- WebSocket Pipeline: Added support for gemini-command executions in backend and payload processing of gemini-response and gemini-error streams in useChatRealtimeHandlers.ts. Resolved JSON double-stringification and sessionId stripping issues in the transmission handler.
- Platform Compatibility: Added scripts/fix-node-pty.js postinstall script and modified posix_spawnp calls with sh -c wrapper to prevent ENOEXEC and MacOS permission errors when spawning the gemini headless binary.
- UX & Design: Imported official Google Gemini branding via GeminiLogo.jsx and gemini-ai-icon.svg. Updated translations (chat.json) for en, zh-CN, and ko locales.

* fix: propagate gemini permission mode from settings to cli

- Added Gemini Permissions UI in Settings to toggle Auto Edit and YOLO modes
- Synced gemini permission mode to localStorage
- Passed permissionMode in useChatComposerState for Gemini commands
- Mapped frontend permission modes to --yolo and --approval-mode options in gemini-cli.js

* feat(gemini): Refactor Gemini CLI integration to use stream-json

- Replaced regex buffering text-system with NDJSON stream parsing
- Added fallback for restricted models like gemini-3.1-pro-preview

* feat(gemini): Render tool_use and tool_result UI bubbles

- Forwarded gemini tool NDJSON objects to the websocket
- Added React state handlers in useChatRealtimeHandlers to match Claude's tool UI behavior

* feat(gemini): Add native session resumption and UI token tracking

- Captured cliSessionId from init events to map ClaudeCodeUI's chat sessionId directly into Gemini's internal session manager.
- Updated gemini-cli.js spawn arguments to append the --resume proxy flag instead of naively dumping the accumulated chat history into the command prompt.
- Handled result stream objects by proxying total_tokens back into the frontend's claude-status tracker to natively populate the UI label.
- Eliminated gemini-3 model proxy filter entirely.

* fix(gemini): Fix static 'Claude' name rendering in chat UI header

- Added "gemini": "Gemini" translation strings to messageTypes across English, Korean, and Chinese loc dictionaries.
- Updated AssistantThinkingIndicator and MessageComponent ternary checks to identify provider === 'gemini' and render the appropriate brand label instead of statically defaulting to Claude.

* feat: Add Gemini session persistence API mapping and Sidebar UI

* fix(gemini): Watch ~/.gemini/sessions for live UI updates

Added the .gemini/sessions directory to PROVIDER_WATCH_PATHS so that Chokidar emits projects_updated websocket events when new Gemini sessions are created or modified, fixing live sidebar updates.

* fix(gemini): Fix Gemini authentication status display in Settings UI

- Injected 'checkGeminiAuthStatus' into the Settings.jsx React effect hook so that the UI can poll and render the 'geminiAuthStatus' state.
- Updated 'checkGeminiCredentials()' inside server/routes/cli-auth.js to read from '~/.gemini/oauth_creds.json' and '~/.gemini/google_accounts.json', resolving the email address correctly.

* Use logo-only icon for gemini

* feat(gemini): Add Gemini 3 preview models to UI selection list

* Fix Gemini CLI session resume bug and PR #422 review nitpicks

* Fix Gemini tool calls disappearing from UI after completion

* fix(gemini): resolve outstanding PR #422 feedback and stabilize gemini CLI timeouts

* fix(gemini): resolve resume flag and shell session initialization issues

This commit addresses the remaining PR comments for the Gemini CLI integration:

- Moves the `--resume` flag logic outside the prompt command block, ensuring Gemini sessions correctly resume even when a new prompt isn't passed.

- Updates `handleShellConnection` to correctly lookup the native `cliSessionId` from the internal `sessionId` when spawning Gemini sessions in a plain shell.

- Refactors dynamic import of `sessionManager.js` back to a native static import for code consistency.

* chore: fix TypeScript errors and remove gemini CLI dependency

* fix: use cross-spawn on Windows to resolve gemini.cmd correctly

---------

Co-authored-by: Haileyesus <118998054+blackmammoth@users.noreply.github.com>

server/routes/agent.js

@@ -9,6 +9,7 @@ import { addProjectManually } from '../projects.js';
 import { queryClaudeSDK } from '../claude-sdk.js';
 import { spawnCursor } from '../cursor-cli.js';
 import { queryCodex } from '../openai-codex.js';
+import { spawnGemini } from '../gemini-cli.js';
 import { Octokit } from '@octokit/rest';
 import { CLAUDE_MODELS, CURSOR_MODELS, CODEX_MODELS } from '../../shared/modelConstants.js';
 import { IS_PLATFORM } from '../constants/config.js';
@@ -629,7 +630,7 @@ class ResponseCollector {
  *                          - Source for auto-generated branch names (if createBranch=true and no branchName)
  *                          - Fallback for PR title if no commits are made
  *
- * @param {string} provider - (Optional) AI provider to use. Options: 'claude' | 'cursor'
+ * @param {string} provider - (Optional) AI provider to use. Options: 'claude' | 'cursor' | 'codex' | 'gemini'
  *                           Default: 'claude'
  *
  * @param {boolean} stream - (Optional) Enable Server-Sent Events (SSE) streaming for real-time updates.
@@ -747,7 +748,7 @@ class ResponseCollector {
  * Input Validations (400 Bad Request):
  *   - Either githubUrl OR projectPath must be provided (not neither)
  *   - message must be non-empty string
- *   - provider must be 'claude' or 'cursor'
+ *   - provider must be 'claude', 'cursor', 'codex', or 'gemini'
  *   - createBranch/createPR requires githubUrl OR projectPath (not neither)
  *   - branchName must pass Git naming rules (if provided)
  *
@@ -855,8 +856,8 @@ router.post('/', validateExternalApiKey, async (req, res) => {
     return res.status(400).json({ error: 'message is required' });
   }
 
-  if (!['claude', 'cursor', 'codex'].includes(provider)) {
-    return res.status(400).json({ error: 'provider must be "claude", "cursor", or "codex"' });
+  if (!['claude', 'cursor', 'codex', 'gemini'].includes(provider)) {
+    return res.status(400).json({ error: 'provider must be "claude", "cursor", "codex", or "gemini"' });
   }
 
   // Validate GitHub branch/PR creation requirements
@@ -971,6 +972,16 @@ router.post('/', validateExternalApiKey, async (req, res) => {
         model: model || CODEX_MODELS.DEFAULT,
         permissionMode: 'bypassPermissions'
       }, writer);
+    } else if (provider === 'gemini') {
+      console.log('✨ Starting Gemini CLI session');
+
+      await spawnGemini(message.trim(), {
+        projectPath: finalProjectPath,
+        cwd: finalProjectPath,
+        sessionId: null,
+        model: model,
+        skipPermissions: true // CLI mode bypasses permissions
+      }, writer);
     }
 
     // Handle GitHub branch and PR creation after successful agent completion