refactor: align backend layout and supabase infra

Consolidate backend modules/tests under the backend package while syncing Supabase compose/env config and related plans.

pyproject.toml

@@ -4,11 +4,18 @@ version = "0.1.0"
 description = "Social application backend"
 requires-python = ">=3.12"
 dependencies = [
+    "alembic>=1.18.3",
+    "asyncpg>=0.31.0",
     "basedpyright>=1.37.2",
     "celery>=5.6.2",
+    "email-validator>=2.3.0",
     "fastapi>=0.128.0",
     "pydantic>=2.11.0",
     "pydantic-settings>=2.10.0",
+    "pyjwt>=2.10.1",
+    "qdrant-client>=1.16.2",
+    "redis>=7.1.0",
+    "sqlalchemy[asyncio]>=2.0.46",
     "structlog>=24.4.0",
     "supabase>=2.27.2",
     "uvicorn[standard]>=0.40.0",
@@ -28,11 +35,12 @@ url = "https://pypi.tuna.tsinghua.edu.cn/simple"
 default = true
 
 [tool.pytest.ini_options]
-testpaths = ["api/tests"]
+testpaths = ["backend/tests"]
 addopts = "-q"
 asyncio_mode = "auto"
 
 [dependency-groups]
 dev = [
+    "aiosqlite>=0.22.1",
     "pre-commit>=4.5.1",
 ]