Crypto trading bot: engine, brokers, backtester, dashboard, deploy

FastAPI backend with a single-strategy async engine, paper and Binance
brokers, pure-python indicators, a backtester that shares the engine's
portfolio math, and a Vue dashboard with a live WebSocket feed. Adds the
Gitea Actions CI/CD workflow that deploys to Traefik via docker_default.

.gitignore

@@ -0,0 +1,28 @@
+# Python
+__pycache__/
+*.py[cod]
+.venv/
+venv/
+*.egg-info/
+.pytest_cache/
+.ruff_cache/
+.mypy_cache/
+
+# Data / runtime
+data/
+*.db
+*.sqlite3
+*.log
+
+# Env / secrets
+.env
+
+# Frontend
+node_modules/
+frontend/dist/
+frontend/.vite/
+
+# Editors / OS
+.vscode/
+.idea/
+.DS_Store