feat(backend): add /api/health endpoint for k8s readiness probe

backend/app.py

@@ -105,6 +105,20 @@ def delete_task(task_id):
     return jsonify({"result": "ok"})
 
 
+@app.route("/api/health", methods=["GET"])
+def health():
+    try:
+        conn = get_db()
+        cur = conn.cursor()
+        cur.execute("SELECT 1")
+        cur.fetchone()
+        cur.close()
+        conn.close()
+        return jsonify({"status": "ok"}), 200
+    except Exception as exc:
+        return jsonify({"status": "unhealthy", "error": str(exc)}), 503
+
+
 if __name__ == "__main__":
     init_db()
     app.run(host="0.0.0.0", port=5000)