fix: address project review findings

Security and robustness:
- storage-agent rejects an empty INTERNAL_TOKEN (config notEmpty + middleware)
- api takes the client IP only from X-Real-IP (chi RealIP trusted True-Client-IP)
- /readyz reports ok/fail and logs the cause; checks run in parallel with a timeout
- storage-agent shuts down gracefully; shared httpx.NewServer/Serve with IdleTimeout
- goose migrations take a Postgres advisory lock
- recommender readyz: per-check timeout, redis socket timeouts

Clients:
- Android release allows cleartext HTTP for LAN servers (expo-build-properties)
- checkServer times out after 10s; connect button is disabled while checking

Deploy and CI:
- install.sh hands cache/uploads/updates/models to the non-root service users
- update.sh refuses downgrades unless PIPU_ALLOW_DOWNGRADE=1
- recommender/analyzer get only the env they need; required secrets fail fast
- nginx security headers and CSP; strip True-Client-IP
- dev compose binds ports to 127.0.0.1; postgres/redis images pinned
- version.mjs fails on a malformed explicit tag instead of releasing 0.0.0-dev
- contract check catches untracked generated files
- final releases fail without a release keystore; changelog skips rc tags

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

services/recommender/tests/test_app.py

@@ -32,7 +32,21 @@ def test_readyz_all_up() -> None:
 def test_readyz_dependency_down() -> None:
     r = client({"postgres": ok, "redis": down}).get("/readyz")
     assert r.status_code == 503
-    assert r.json()["checks"]["redis"] == "connection refused"
+    assert r.json()["checks"]["redis"] == "fail"
+
+
+def test_readyz_dependency_hangs(monkeypatch) -> None:  # type: ignore[no-untyped-def]
+    import asyncio
+
+    from pipu_rec.api import app as app_module
+
+    async def hang() -> None:
+        await asyncio.sleep(10)
+
+    monkeypatch.setattr(app_module, "CHECK_TIMEOUT_S", 0.05)
+    r = client({"postgres": ok, "redis": hang}).get("/readyz")
+    assert r.status_code == 503
+    assert r.json()["checks"] == {"postgres": "ok", "redis": "fail"}
 
 
 def test_internal_status_requires_token() -> None: