docs: add comprehensive README and update .gitignore

.gitignore

@@ -1,18 +1,67 @@
-# Dependencies
-frontend/node_modules/
-frontend/package-lock.json
+# Python
+__pycache__/
+*.py[cod]
+*$py.class
+*.so
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+*.egg-info/
+.installed.cfg
+*.egg
 
-# Build output
-frontend/dist/
-
-# Environment files
-.env
-.env.local
+# Virtual environments
+venv/
+.venv/
+env/
+ENV/
 
 # IDE
 .vscode/
 .idea/
+*.swp
+*.swo
+*~
 
 # OS
 .DS_Store
 Thumbs.db
+
+# Environment files
+.env
+.env.local
+.env.*.local
+
+# Database
+*.db
+*.sqlite
+*.sqlite3
+
+# Frontend
+frontend/node_modules/
+frontend/dist/
+frontend/package-lock.json
+frontend/yarn.lock
+frontend/pnpm-lock.yaml
+
+# Logs
+*.log
+logs/
+
+# Testing
+.pytest_cache/
+.coverage
+htmlcov/
+
+# Backup tool specific
+backups/