feat: add dataset checkpoint sync for MCP

tests/test_api_mcp.py

@@ -1,3 +1,4 @@
+import json
 from datetime import datetime, timezone
 from types import SimpleNamespace
 
@@ -19,7 +20,7 @@ def test_health_returns_versions():
     response = client.get("/api/health")
 
     assert response.status_code == 200
-    assert response.json()["backend_version"] == "0.4.7"
+    assert response.json()["backend_version"] == "0.5.0"
 
 
 def test_mcp_lists_tools_without_auth_and_ignores_auth_header():
@@ -50,7 +51,10 @@ def test_mcp_lists_tools_without_auth_and_ignores_auth_header():
 
     assert without_auth.status_code == 200
     assert with_auth.status_code == 200
-    assert without_auth.json()["result"]["tools"][0]["name"] == "search_employees"
+    tool_names = {tool["name"] for tool in without_auth.json()["result"]["tools"]}
+    assert "search_employees" in tool_names
+    assert "get_service_info" in tool_names
+    assert "sync_employees" in tool_names
     assert any(tool["name"] == "get_crawl_run_details" for tool in without_auth.json()["result"]["tools"])
     assert with_auth.json()["result"]["tools"] == without_auth.json()["result"]["tools"]
 
@@ -108,6 +112,128 @@ def test_mcp_search_employees_returns_matching_employee():
     app.dependency_overrides.clear()
 
 
+def test_mcp_service_info_returns_tools_and_dataset_hash():
+    engine = create_engine(
+        "sqlite:///:memory:",
+        connect_args={"check_same_thread": False},
+        poolclass=StaticPool,
+    )
+    Base.metadata.create_all(engine)
+    Session = sessionmaker(bind=engine)
+    session = Session()
+    session.add(
+        Employee(
+            profile_key="staff:alpha",
+            profile_type="staff",
+            profile_id="alpha",
+            canonical_url="https://www.hse.ru/staff/alpha",
+            full_name="Alpha Person",
+            status="active",
+            current_checksum="a" * 64,
+            current_data={"sections": []},
+        )
+    )
+    session.commit()
+    session.close()
+
+    def override_db():
+        db = Session()
+        try:
+            yield db
+        finally:
+            db.close()
+
+    app.dependency_overrides[get_db] = override_db
+    client = TestClient(app)
+
+    response = client.post(
+        "/mcp",
+        json={"jsonrpc": "2.0", "id": 1, "method": "tools/call", "params": {"name": "get_service_info", "arguments": {}}},
+    )
+
+    assert response.status_code == 200
+    payload = json.loads(response.json()["result"]["content"][0]["text"])
+    assert payload["service_name"] == "miem-employees"
+    assert payload["backend_version"] == "0.5.0"
+    assert payload["dataset"]["hash"]
+    assert any(tool["name"] == "sync_employees" for tool in payload["tools"])
+
+    app.dependency_overrides.clear()
+
+
+def test_mcp_sync_employees_full_empty_and_unknown_hash_modes():
+    engine = create_engine(
+        "sqlite:///:memory:",
+        connect_args={"check_same_thread": False},
+        poolclass=StaticPool,
+    )
+    Base.metadata.create_all(engine)
+    Session = sessionmaker(bind=engine)
+    session = Session()
+    session.add(
+        Employee(
+            profile_key="staff:alpha",
+            profile_type="staff",
+            profile_id="alpha",
+            canonical_url="https://www.hse.ru/staff/alpha",
+            full_name="Alpha Person",
+            status="active",
+            current_checksum="a" * 64,
+            current_data={"sections": [{"type": "paragraphs"}]},
+        )
+    )
+    session.commit()
+    session.close()
+
+    def override_db():
+        db = Session()
+        try:
+            yield db
+        finally:
+            db.close()
+
+    app.dependency_overrides[get_db] = override_db
+    client = TestClient(app)
+
+    full_response = client.post(
+        "/mcp",
+        json={"jsonrpc": "2.0", "id": 1, "method": "tools/call", "params": {"name": "sync_employees", "arguments": {}}},
+    )
+    full_payload = json.loads(full_response.json()["result"]["content"][0]["text"])
+    current_hash = full_payload["to_hash"]
+
+    empty_response = client.post(
+        "/mcp",
+        json={
+            "jsonrpc": "2.0",
+            "id": 2,
+            "method": "tools/call",
+            "params": {"name": "sync_employees", "arguments": {"client_hash": current_hash}},
+        },
+    )
+    empty_payload = json.loads(empty_response.json()["result"]["content"][0]["text"])
+
+    unknown_response = client.post(
+        "/mcp",
+        json={
+            "jsonrpc": "2.0",
+            "id": 3,
+            "method": "tools/call",
+            "params": {"name": "sync_employees", "arguments": {"client_hash": "missing"}},
+        },
+    )
+    unknown_payload = json.loads(unknown_response.json()["result"]["content"][0]["text"])
+
+    assert full_payload["mode"] == "full"
+    assert full_payload["items"][0]["data"] == {"sections": [{"type": "paragraphs"}]}
+    assert empty_payload["mode"] == "delta"
+    assert empty_payload["changes"] == {"added": [], "updated": [], "dismissed": [], "removed": []}
+    assert unknown_payload["mode"] == "full"
+    assert unknown_payload["reason"] == "unknown_client_hash"
+
+    app.dependency_overrides.clear()
+
+
 def test_mcp_get_crawl_run_details_returns_changes():
     engine = create_engine(
         "sqlite:///:memory:",