Initial commit: Happy Up monorepo through Sprint 5.

Document-driven MVP with FastAPI backend, Vue H5, WeChat mini shell, product demo, and Docker dev stack.

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/api/app/db/session.py

@@ -0,0 +1,23 @@
+from sqlalchemy import create_engine
+from sqlalchemy.orm import DeclarativeBase, sessionmaker
+
+from app.config import settings
+
+engine = create_engine(settings.database_url, pool_pre_ping=True, future=True)
+SessionLocal = sessionmaker(bind=engine, autoflush=False, autocommit=False, future=True)
+
+
+class Base(DeclarativeBase):
+    pass
+
+
+def get_db():
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()
+
+
+# Ensure models are registered on metadata for Alembic/tests.
+from app.db import models as _models  # noqa: E402,F401