feat(proxy): add request parsing

tests/unit/test_proxy.py

@@ -0,0 +1,26 @@
+import pytest
+from grist_mcp.proxy import parse_proxy_request, ProxyRequest, ProxyError
+
+
+def test_parse_proxy_request_valid_add_records():
+    body = {
+        "method": "add_records",
+        "table": "Orders",
+        "records": [{"item": "Widget", "qty": 10}],
+    }
+
+    request = parse_proxy_request(body)
+
+    assert request.method == "add_records"
+    assert request.table == "Orders"
+    assert request.records == [{"item": "Widget", "qty": 10}]
+
+
+def test_parse_proxy_request_missing_method():
+    body = {"table": "Orders"}
+
+    with pytest.raises(ProxyError) as exc_info:
+        parse_proxy_request(body)
+
+    assert exc_info.value.code == "INVALID_REQUEST"
+    assert "method" in str(exc_info.value)