fix: resolve CI linting errors for Python and ESLint

Python (ruff F401 - unused imports):
- Remove unused DEFAULT_YOLO_MODE import from server/routers/settings.py
- Remove unused AVAILABLE_MODELS import from server/schemas.py

ESLint (missing config for v9):
- Add ui/eslint.config.js with flat config format for ESLint v9
- Configure TypeScript, React Hooks, and React Refresh plugins
- Fix unnecessary regex escapes in AgentThought.tsx
- Remove unused onComplete from useSpecChat.ts dependency array

Additional:
- Add .claude/commands/check-code.md for local CI verification

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.claude/commands/check-code.md

@@ -0,0 +1,32 @@
+---
+description:
+---
+
+Run the following commands and ensure the code is clean.
+
+From project root:
+
+# Python linting
+
+ruff check .
+
+# Security tests
+
+python test_security.py
+
+From ui/ directory:
+cd ui
+
+# ESLint (will fail until we add the config)
+
+npm run lint
+
+# TypeScript check + build
+
+npm run build
+
+One-liner to run everything:
+ruff check . && python test_security.py && cd ui && npm run lint && npm run build
+
+Or if you want to see all failures at once (doesn't stop on first error):
+ruff check .; python test_security.py; cd ui && npm run lint; npm run build

server/routers/settings.py

@@ -21,7 +21,6 @@ if str(ROOT_DIR) not in sys.path:
 from registry import (
     AVAILABLE_MODELS,
     DEFAULT_MODEL,
-    DEFAULT_YOLO_MODE,
     get_all_settings,
     set_setting,
 )

server/schemas.py

@@ -18,7 +18,7 @@ _root = Path(__file__).parent.parent
 if str(_root) not in sys.path:
     sys.path.insert(0, str(_root))
 
-from registry import AVAILABLE_MODELS, DEFAULT_MODEL, VALID_MODELS
+from registry import DEFAULT_MODEL, VALID_MODELS
 
 # ============================================================================
 # Project Schemas

ui/eslint.config.js

@@ -0,0 +1,28 @@
+import js from '@eslint/js'
+import globals from 'globals'
+import reactHooks from 'eslint-plugin-react-hooks'
+import reactRefresh from 'eslint-plugin-react-refresh'
+import tseslint from 'typescript-eslint'
+
+export default tseslint.config(
+  { ignores: ['dist'] },
+  {
+    extends: [js.configs.recommended, ...tseslint.configs.recommended],
+    files: ['**/*.{ts,tsx}'],
+    languageOptions: {
+      ecmaVersion: 2020,
+      globals: globals.browser,
+    },
+    plugins: {
+      'react-hooks': reactHooks,
+      'react-refresh': reactRefresh,
+    },
+    rules: {
+      ...reactHooks.configs.recommended.rules,
+      'react-refresh/only-export-components': [
+        'warn',
+        { allowConstantExport: true },
+      ],
+    },
+  },
+)

ui/src/components/AgentThought.tsx

@@ -24,7 +24,7 @@ function isAgentThought(line: string): boolean {
   if (/^Output:/.test(trimmed)) return false
 
   // Skip JSON and very short lines
-  if (/^[\[\{]/.test(trimmed)) return false
+  if (/^[[{]/.test(trimmed)) return false
   if (trimmed.length < 15) return false
 
   // Skip lines that are just paths or technical output

ui/src/hooks/useSpecChat.ts

@@ -33,7 +33,7 @@ function generateId(): string {
 
 export function useSpecChat({
   projectName,
-  onComplete,
+  // onComplete intentionally not used - user clicks "Continue to Project" button instead
   onError,
 }: UseSpecChatOptions): UseSpecChatReturn {
   const [messages, setMessages] = useState<ChatMessage[]>([])
@@ -346,7 +346,7 @@ export function useSpecChat({
         console.error('Failed to parse WebSocket message:', e)
       }
     }
-  }, [projectName, onComplete, onError])
+  }, [projectName, onError])
 
   const start = useCallback(() => {
     connect()