test: Reorganize organization member tests into proper pytest structure

Fix test organization by moving ad-hoc test scripts into proper pytest tests
following project conventions. Added 4 new tests to integration and e2e layers
to provide comprehensive coverage for organization members.

Changes:
- tests/integration/test_member_mutations.py:
  * Add test_create_organization_member - Tests creating organizations with companyName
  * Add test_create_organization_with_contact_person - Tests organizations with contact info
  * Import MemberType from models and schemas

- tests/integration/test_member_queries.py:
  * Add test_query_mixed_member_types - Tests querying both individual and organization members
  * Import MemberType from models

- tests/e2e/test_graphql_api.py:
  * Add test_introspect_member_type_enum - Tests GraphQL introspection for MemberType enum
  * Verifies INDIVIDUAL and ORGANIZATION enum values

Deleted improper test files:
- test_organization_members.py (root) - Ad-hoc script using httpx directly
- test_mcp_changes.sh (root) - Shell script for MCP server testing

Test results:
- All 57 tests pass (up from 53)
- Organization members now tested at all layers: unit, integration, and e2e
- Tests follow pytest conventions with async patterns and shared fixtures
- Integrated with CI/CD pipeline (proper test/ directory structure)

The proper test structure ensures:
1. Unit tests validate business logic (validation layer)
2. Integration tests verify GraphQL resolvers and database persistence
3. E2E tests confirm full HTTP request/response flows
4. All tests use shared fixtures from conftest.py

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

tests/e2e/test_graphql_api.py

@@ -153,3 +153,31 @@ class TestGraphQLAPI:
         # The error should mention validation
         error_message = str(data["errors"])
         assert "Invalid email format" in error_message or "email" in error_message.lower()
+
+    async def test_introspect_member_type_enum(self, graphql_client):
+        """Test GraphQL introspection returns MemberType enum."""
+        query = """
+        query {
+            __type(name: "MemberType") {
+                name
+                kind
+                enumValues {
+                    name
+                }
+            }
+        }
+        """
+
+        response = await graphql_client.post("/graphql", json={"query": query})
+        assert response.status_code == 200
+
+        data = response.json()
+        assert "data" in data
+
+        member_type = data["data"]["__type"]
+        assert member_type["name"] == "MemberType"
+        assert member_type["kind"] == "ENUM"
+
+        enum_values = {ev["name"] for ev in member_type["enumValues"]}
+        assert "INDIVIDUAL" in enum_values
+        assert "ORGANIZATION" in enum_values