feat: Add GitHub Actions CI for PR protection

- Add CI workflow with Python (ruff lint, security tests) and UI (ESLint, TypeScript, build) jobs
- Add ruff, mypy, pytest to requirements.txt
- Add pyproject.toml with ruff configuration
- Fix import sorting across Python files (ruff --fix)
- Fix test_security.py expectations to match actual security policy
- Remove invalid 'eof' command from ALLOWED_COMMANDS

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

server/routers/filesystem.py

@@ -18,14 +18,13 @@ from fastapi import APIRouter, HTTPException, Query
 logger = logging.getLogger(__name__)
 
 from ..schemas import (
+    CreateDirectoryRequest,
     DirectoryEntry,
     DirectoryListResponse,
     DriveInfo,
     PathValidationResponse,
-    CreateDirectoryRequest,
 )
 
-
 router = APIRouter(prefix="/api/filesystem", tags=["filesystem"])