feat(admin): finalizing modular refactoring with testing suite and UI polish

backend/tests/conftest.py

@@ -0,0 +1,65 @@
+import pytest
+from fastapi.testclient import TestClient
+from sqlalchemy import create_engine
+from sqlalchemy.orm import sessionmaker
+from sqlalchemy.pool import StaticPool
+
+from backend.database import Base, get_db
+from backend.main import app
+from backend.auth import get_current_admin, TokenData
+
+from datetime import datetime, timezone
+
+# Use in-memory SQLite for tests
+SQLALCHEMY_DATABASE_URL = "sqlite://"
+
+engine = create_engine(
+    SQLALCHEMY_DATABASE_URL,
+    connect_args={"check_same_thread": False},
+    poolclass=StaticPool,
+)
+TestingSessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+
+@pytest.fixture(scope="function", autouse=True)
+def mock_scheduler():
+    from backend.scheduler import scheduler
+    if scheduler.running:
+        scheduler.shutdown()
+    yield
+    if scheduler.running:
+        scheduler.shutdown()
+
+@pytest.fixture(scope="function")
+def db():
+    Base.metadata.create_all(bind=engine)
+    session = TestingSessionLocal()
+    try:
+        yield session
+    finally:
+        session.close()
+        Base.metadata.drop_all(bind=engine)
+
+@pytest.fixture(scope="function")
+def client(db):
+    def override_get_db():
+        try:
+            yield db
+        finally:
+            pass
+    
+    # Mock admin user with valid TokenData
+    def override_get_current_admin():
+        return TokenData(
+            sub=1, 
+            username="admin", 
+            role="admin", 
+            exp=datetime.now(timezone.utc)
+        )
+
+    app.dependency_overrides[get_db] = override_get_db
+    app.dependency_overrides[get_current_admin] = override_get_current_admin
+    
+    with TestClient(app) as c:
+        yield c
+    
+    app.dependency_overrides.clear()