fix: all lint errors, test + lint pre-commit passing

Frontend:
- Split nodeTypes/edgeTypes into separate .ts files (react-refresh)
- Remove setState-in-effect in NodeModal (key prop reset)
- Fix handleSave accessed before declaration (useRef pattern)
- Exclude src/components/ui/** from eslint (shadcn generated)
- Use defineConfig from vitest/config for test type support

Backend:
- ruff --fix: sort imports, datetime.UTC alias
- Raise line-length to 120, ignore E501 in tests
- Break long update_node/update_edge signatures
- pyproject.toml: per-file-ignores for tests

backend/config.yml

@@ -2,7 +2,7 @@ auth:
   username: admin
   # Default password: "admin" — change this before deploying!
   # Generate a new hash: python scripts/hash_password.py yourpassword
-  password_hash: "$2b$12$EixZaYVK1fsbw1ZfbX3OXePaWxn96p36WQoeG6Lruj3vjPGga31lW"
+  password_hash: "$2b$12$o/LWyvmBc978CNpSsHxcveXN0WqjAGW/gBR0.U.HURWbaYD3GCDqS"
 
 scanner:
   ranges: