chore: remove unused websockets.exceptions import, add .gitignore, untrack __pycache__

- Remove unused 'import websockets.exceptions' from main.py (no reference
  to websockets.exceptions.* anywhere in the file; all WS handlers use
  broad Exception catches)
- Add .gitignore with __pycache__/, *.pyc, .venv/, and other standard
  Python excludes so bytecode no longer shows as modified in git status
- Untrack all pre-existing __pycache__/*.pyc files via git rm --cached

.gitignore

@@ -0,0 +1,30 @@
+# Python bytecode
+__pycache__/
+*.pyc
+*.pyo
+*.pyd
+
+# Virtual environment
+.venv/
+venv/
+env/
+
+# Distribution / packaging
+dist/
+build/
+*.egg-info/
+
+# Test/coverage artifacts
+.coverage
+.pytest_cache/
+htmlcov/
+
+# OS artifacts
+.DS_Store
+Thumbs.db
+
+# IDE
+.idea/
+.vscode/
+*.swp
+*.swo