chore: initialize lhbfx project and documentation

.gitignore

@@ -0,0 +1,33 @@
+# OS / editor
+.DS_Store
+Thumbs.db
+.idea/
+.vscode/
+
+# Local runtime data
+logs/
+output/
+.playwright-cli/
+*.log
+
+# Python
+__pycache__/
+*.py[cod]
+*.pyo
+*.pyd
+.pytest_cache/
+.mypy_cache/
+
+# Node / frontend
+frontend/node_modules/
+frontend/dist/
+frontend/.vite/
+frontend/.vite-temp/
+
+# Sensitive or machine-local config
+backend/config.yaml
+
+# Temp / debug files
+_tmp_*.json
+_curl_*.json
+*.tmp