refactor: reorganize tests into admin and vendor subdirectories

Split integration tests into logical admin/ and vendor/ subdirectories
for better organization. Updated fixture imports and test structure.

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

tests/integration/api/v1/admin/test_users.py

@@ -0,0 +1,120 @@
+# tests/integration/api/v1/admin/test_users.py
+"""Integration tests for admin user management endpoints.
+
+Tests the /api/v1/admin/users/* endpoints.
+"""
+import pytest
+
+
+@pytest.mark.integration
+@pytest.mark.api
+@pytest.mark.admin
+class TestAdminUsersAPI:
+    """Test admin user management endpoints at /api/v1/admin/users/*."""
+
+    def test_get_all_users_admin(self, client, admin_headers, test_user):
+        """Test admin getting all users."""
+        response = client.get("/api/v1/admin/users", headers=admin_headers)
+
+        assert response.status_code == 200
+        data = response.json()
+        # Response is paginated with items, total, page, per_page, pages
+        assert "items" in data
+        assert "total" in data
+        assert "page" in data
+        assert "per_page" in data
+        assert "pages" in data
+        assert data["total"] >= 2  # test_user + admin user
+
+        # Check that test_user is in the response
+        user_ids = [user["id"] for user in data["items"] if "id" in user]
+        assert test_user.id in user_ids
+
+    def test_get_all_users_non_admin(self, client, auth_headers):
+        """Test non-admin trying to access admin endpoint."""
+        response = client.get("/api/v1/admin/users", headers=auth_headers)
+
+        assert response.status_code == 403
+        data = response.json()
+        assert data["error_code"] == "ADMIN_REQUIRED"
+        assert "Admin privileges required" in data["message"]
+
+    def test_toggle_user_status_admin(self, client, admin_headers, test_user):
+        """Test admin toggling user status."""
+        response = client.put(
+            f"/api/v1/admin/users/{test_user.id}/status", headers=admin_headers
+        )
+
+        assert response.status_code == 200
+        message = response.json()["message"]
+        assert "deactivated" in message or "activated" in message
+        assert test_user.username in message
+
+    def test_toggle_user_status_user_not_found(self, client, admin_headers):
+        """Test admin toggling status for non-existent user."""
+        response = client.put("/api/v1/admin/users/99999/status", headers=admin_headers)
+
+        assert response.status_code == 404
+        data = response.json()
+        assert data["error_code"] == "USER_NOT_FOUND"
+        assert "User with ID '99999' not found" in data["message"]
+
+    def test_toggle_user_status_cannot_modify_self(
+        self, client, admin_headers, test_admin
+    ):
+        """Test that admin cannot modify their own account."""
+        response = client.put(
+            f"/api/v1/admin/users/{test_admin.id}/status", headers=admin_headers
+        )
+
+        assert response.status_code == 400
+        data = response.json()
+        assert data["error_code"] == "CANNOT_MODIFY_SELF"
+        assert (
+            "Cannot perform 'deactivate account' on your own account" in data["message"]
+        )
+
+    def test_toggle_user_status_cannot_modify_admin(
+        self, client, admin_headers, test_admin, another_admin
+    ):
+        """Test that admin cannot modify another admin."""
+        response = client.put(
+            f"/api/v1/admin/users/{another_admin.id}/status", headers=admin_headers
+        )
+
+        assert response.status_code == 400
+        data = response.json()
+        assert data["error_code"] == "USER_STATUS_CHANGE_FAILED"
+        assert "Cannot modify another admin user" in data["message"]
+
+    def test_get_user_statistics(self, client, admin_headers):
+        """Test admin getting user statistics."""
+        response = client.get("/api/v1/admin/users/stats", headers=admin_headers)
+
+        assert response.status_code == 200
+        data = response.json()
+        assert "total_users" in data
+        assert "active_users" in data
+        assert "inactive_users" in data
+        assert "activation_rate" in data
+        assert isinstance(data["total_users"], int)
+
+    def test_admin_pagination_users(self, client, admin_headers, test_user, test_admin):
+        """Test user pagination works correctly."""
+        response = client.get(
+            "/api/v1/admin/users?page=1&per_page=1", headers=admin_headers
+        )
+        assert response.status_code == 200
+        data = response.json()
+        assert "items" in data
+        assert len(data["items"]) == 1
+        assert data["per_page"] == 1
+
+        # Test second page
+        response = client.get(
+            "/api/v1/admin/users?page=2&per_page=1", headers=admin_headers
+        )
+        assert response.status_code == 200
+        data = response.json()
+        assert "items" in data
+        assert len(data["items"]) >= 0