feat(api): enhance authentication and health check endpoints with detailed responses and descriptions

backend/app/schemas/health.py

@@ -0,0 +1,16 @@
+"""Health and readiness probe response schemas."""
+
+from __future__ import annotations
+
+from pydantic import Field
+from sqlmodel import SQLModel
+
+
+class HealthStatusResponse(SQLModel):
+    """Standard payload for service liveness/readiness checks."""
+
+    ok: bool = Field(
+        description="Indicates whether the probe check succeeded.",
+        examples=[True],
+    )
+