feat: add unified linting scripts and git hooks for code quality enforcement

- Introduced `lint` and `lint-fix` applications in `flake.nix` for unified linting of backend (Python) and frontend (TypeScript/Svelte) code.
- Added `scripts/lint.sh` for manual linting execution.
- Created `scripts/install-hooks.sh` to set up git hooks for automatic linting before commits and optional tests before pushes.
- Updated `README.md` with instructions for using the new linting features and git hooks.

backend/app/core/middleware.py

@@ -2,7 +2,6 @@
 
 from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
-from fastapi.middleware.trustedhost import TrustedHostMiddleware
 
 from app.core.config import settings
 
@@ -26,4 +25,3 @@ def setup_middleware(app: FastAPI) -> None:
     #     TrustedHostMiddleware,
     #     allowed_hosts=["yourdomain.com", "*.yourdomain.com"]
     # )
-