Add browser Python editor with Pyodide, user auth, and workspace API

- FastAPI serves static UI, file CRUD under code/ and read-only lib/
- Pyodide worker runs Python and Jedi completions in the browser
- SQLite accounts: login/register, session cookies, superuser user management
- Optional EDITOR_API_KEY, AUTH_* env vars, .env.example
- Pipenv, pytest, Selenium smoke test, README

Made-with: Cursor

.gitignore

@@ -15,8 +15,8 @@ dist/
 downloads/
 eggs/
 .eggs/
-lib/
-lib64/
+/lib/
+/lib64/
 parts/
 sdist/
 var/
@@ -128,6 +128,9 @@ celerybeat.pid
 # SageMath parsed files
 *.sage.py
 
+# Local auth database (default path)
+/data/
+
 # Environments
 .env
 .venv