fix: restore native PostgreSQL readiness probes (#50)

REQUIREMENTS.md

@@ -2,7 +2,7 @@
 
 > **Note:** This document is automatically generated and verified against the live test suite by `scripts/generate_requirements.py` and `tests/backend/test_requirements_sync.py`.
 
-**Test Verification Baseline:** **1115 Automated Tests** (757 Pytest Backend + 308 Vitest Frontend + 50 Playwright E2E).
+**Test Verification Baseline:** **1117 Automated Tests** (759 Pytest Backend + 308 Vitest Frontend + 50 Playwright E2E).
 
 ---
 
@@ -1126,6 +1126,10 @@ and leaves the prior indexed state intact without data loss._
 - `test_set_embedding_db_config_persists_to_system_metadata`
 - `test_update_embedding_config_service`
 
+#### `tests/test_native_postgres_readiness.py` (2 tests)
+- `test_native_postgres_readiness_accepts_initialized_schema`
+- `test_native_postgres_missing_schema_is_sanitized`
+
 #### `tests/test_pdf_extractor.py` (14 tests)
 - `test_extract_digital_pdf_text`
 - `test_extract_scanned_pdf_triggers_vision_ocr`

app/services/database/connection.py

@@ -4,7 +4,7 @@
 import logging
 from typing import Optional, Dict, Any, Tuple
 
-from sqlalchemy import select, func
+from sqlalchemy import select, func, text
 
 from app.services.database.schema import TABLES
 from app.services.database.engine import (

tests/test_native_postgres_readiness.py

@@ -0,0 +1,61 @@
+import os
+import uuid
+
+import pytest
+from fastapi.testclient import TestClient
+from sqlalchemy import create_engine, text
+from sqlalchemy.engine import make_url
+
+import app.services.database as db_service
+from app.services.database.engine import dispose_global_engine
+from main import app
+
+
+@pytest.fixture
+def postgres_readiness_db(monkeypatch, tmp_path):
+    database_url = os.getenv("TEST_POSTGRES_URL")
+    if not database_url:
+        pytest.skip("TEST_POSTGRES_URL is required for native PostgreSQL tests")
+
+    schema = f"readiness_{uuid.uuid4().hex}"
+    admin_engine = create_engine(database_url)
+    with admin_engine.begin() as conn:
+        conn.execute(text(f"CREATE SCHEMA {schema}"))
+    isolated_url = make_url(database_url).update_query_dict(
+        {"options": f"-csearch_path={schema},public"}
+    )
+    monkeypatch.setenv(
+        "DATABASE_URL", isolated_url.render_as_string(hide_password=False)
+    )
+    dispose_global_engine()
+    try:
+        db_service.init_db(vault_path=str(tmp_path))
+        yield
+    finally:
+        dispose_global_engine()
+        with admin_engine.begin() as conn:
+            conn.execute(text(f"DROP SCHEMA {schema} CASCADE"))
+        admin_engine.dispose()
+
+
+def test_native_postgres_readiness_accepts_initialized_schema(postgres_readiness_db):
+    client = TestClient(app)
+    for endpoint in ("/ready", "/readiness", "/health/ready", "/healthz/ready"):
+        response = client.get(endpoint)
+        assert response.status_code == 200
+        assert response.json()["database"] == {"status": "ok", "type": "postgresql"}
+
+
+def test_native_postgres_missing_schema_is_sanitized(postgres_readiness_db):
+    from app.services.database.engine import get_db_engine
+
+    with get_db_engine().begin() as conn:
+        conn.execute(text("DROP TABLE indexed_files"))
+
+    client = TestClient(app)
+    response = client.get("/readiness")
+    assert response.status_code == 503
+    assert response.json()["database"] == {"status": "error", "type": "postgresql"}
+    assert response.json()["error"] == "Required database schema or metadata unavailable"
+    assert "indexed_files" not in response.text
+    assert client.get("/health").status_code == 200