Scaffold FastAPI backend skeleton with health probes

Phase 0 foundation. uv-managed FastAPI app (package=false, runs from source via uv run). Layered seams in place: app/api for routers, app/core for config (pydantic-settings, fully env-driven) and the async SQLAlchemy engine; service/repository/domain layers land with the data model.

Exposes /health (liveness) and /health/ready (Postgres reachability via SELECT 1, 503 on failure) so the deploy wiring is verifiable before any data model exists. Includes a liveness test and the resolved uv.lock. Ignore pytest/ruff/mypy caches.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Signed-off-by: Justin Paul <justin@jpaul.me>

backend/app/api/health.py

@@ -0,0 +1,41 @@
+"""Liveness and readiness endpoints.
+
+- ``/health``       — liveness: the process is up. No dependencies touched.
+- ``/health/ready`` — readiness: dependencies (Postgres) are reachable.
+
+Orchestrators and Caddy probe these; they are intentionally outside the
+versioned ``/api`` surface.
+"""
+
+from fastapi import APIRouter, Response, status
+from sqlalchemy import text
+
+from app.core.config import get_settings
+from app.core.db import get_engine
+
+router = APIRouter(tags=["health"])
+
+
+@router.get("/health")
+async def health() -> dict:
+    settings = get_settings()
+    return {
+        "status": "ok",
+        "service": settings.app_name,
+        "version": settings.version,
+        "env": settings.app_env,
+    }
+
+
+@router.get("/health/ready")
+async def ready(response: Response) -> dict:
+    checks: dict[str, str] = {}
+    try:
+        async with get_engine().connect() as conn:
+            await conn.execute(text("SELECT 1"))
+        checks["database"] = "ok"
+        return {"status": "ready", "checks": checks}
+    except Exception as exc:  # noqa: BLE001 — surface any failure as "not ready"
+        checks["database"] = "error"
+        response.status_code = status.HTTP_503_SERVICE_UNAVAILABLE
+        return {"status": "not ready", "checks": checks, "detail": str(exc)}