perf: optimize workflow tool responses for token efficiency (v2.29.0) (#479)

* perf: optimize workflow tool responses for token efficiency (v2.29.0)

Reduce response sizes by 75-90% for 4 workflow management tools:

- n8n_update_partial_workflow: Returns {id, name, active, operationsApplied}
- n8n_create_workflow: Returns {id, name, active, nodeCount}
- n8n_update_full_workflow: Returns {id, name, active, nodeCount}
- n8n_delete_workflow: Returns {id, name, deleted: true}

AI agents can use n8n_get_workflow with mode 'structure' if they need
to verify the current workflow state after operations.

Conceived by Romuald Członkowski - https://www.aiadvisors.pl/en

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

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

* fix: update tests and add nodeCount to partial update response

- Fix handleCreateWorkflow test to expect minimal response
- Fix handleDeleteWorkflow test to expect minimal response
- Add nodeCount to n8n_update_partial_workflow response for consistency
- Update documentation and CHANGELOG

Conceived by Romuald Członkowski - https://www.aiadvisors.pl/en

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

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

* fix: update handlers-workflow-diff tests for minimal response

Update 3 more tests that expected full workflow in response:
- should apply diff operations successfully
- should activate workflow after successful update
- should deactivate workflow after successful update

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

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

* fix: update integration tests to use minimal response format

Integration tests now verify minimal response format and use
client.getWorkflow() to fetch actual workflow state for verification.

Conceived by Romuald Czlonkowski - www.aiadvisors.pl/en

* fix: update create/update workflow integration tests for minimal response

Integration tests now verify minimal response and use client.getWorkflow()
to fetch actual workflow state for detailed verification.

Conceived by Romuald Czlonkowski - www.aiadvisors.pl/en

* fix: add type assertions to fix TypeScript errors in tests

Conceived by Romuald Czlonkowski - www.aiadvisors.pl/en

---------

Co-authored-by: Romuald Członkowski <romualdczlonkowski@MacBook-Pro-Romuald.local>
Co-authored-by: Claude <noreply@anthropic.com>

tests/integration/n8n-api/workflows/update-workflow.test.ts

@@ -75,14 +75,18 @@ describe('Integration: handleUpdateWorkflow', () => {
         mcpContext
       );
 
-      // Verify MCP response
+      // Verify MCP response - now returns minimal data
       expect(response.success).toBe(true);
       expect(response.data).toBeDefined();
 
       const updated = response.data as any;
       expect(updated.id).toBe(created.id);
       expect(updated.name).toBe(replacement.name);
-      expect(updated.nodes).toHaveLength(2); // HTTP workflow has 2 nodes
+      expect(updated.nodeCount).toBe(2); // HTTP workflow has 2 nodes
+
+      // Fetch actual workflow to verify
+      const actual = await client.getWorkflow(created.id);
+      expect(actual.nodes).toHaveLength(2);
     });
   });
 
@@ -147,9 +151,14 @@ describe('Integration: handleUpdateWorkflow', () => {
       );
 
       expect(response.success).toBe(true);
+      // Response now returns minimal data
       const updated = response.data as any;
-      expect(updated.nodes).toHaveLength(2);
-      expect(updated.nodes.find((n: any) => n.name === 'Set')).toBeDefined();
+      expect(updated.nodeCount).toBe(2);
+
+      // Fetch actual workflow to verify
+      const actual = await client.getWorkflow(created.id);
+      expect(actual.nodes).toHaveLength(2);
+      expect(actual.nodes.find((n: any) => n.name === 'Set')).toBeDefined();
     });
   });
 
@@ -193,9 +202,13 @@ describe('Integration: handleUpdateWorkflow', () => {
       );
 
       expect(response.success).toBe(true);
+      // Response now returns minimal data
       const updated = response.data as any;
-      // Note: n8n API may not return settings in response
-      expect(updated.nodes).toHaveLength(1); // Nodes unchanged
+      expect(updated.nodeCount).toBe(1); // Nodes unchanged
+
+      // Fetch actual workflow to verify
+      const actual = await client.getWorkflow(created.id);
+      expect(actual.nodes).toHaveLength(1);
     });
   });
 
@@ -294,9 +307,14 @@ describe('Integration: handleUpdateWorkflow', () => {
       );
 
       expect(response.success).toBe(true);
+      // Response now returns minimal data
       const updated = response.data as any;
       expect(updated.name).toBe(newName);
-      expect(updated.nodes).toHaveLength(1); // Structure unchanged
+      expect(updated.nodeCount).toBe(1); // Structure unchanged
+
+      // Fetch actual workflow to verify
+      const actual = await client.getWorkflow(created.id);
+      expect(actual.nodes).toHaveLength(1);
     });
   });
 
@@ -340,9 +358,13 @@ describe('Integration: handleUpdateWorkflow', () => {
       );
 
       expect(response.success).toBe(true);
+      // Response now returns minimal data
       const updated = response.data as any;
       expect(updated.name).toBe(newName);
-      expect(updated.settings?.timezone).toBe('America/New_York');
+
+      // Fetch actual workflow to verify settings
+      const actual = await client.getWorkflow(created.id);
+      expect(actual.settings?.timezone).toBe('America/New_York');
     });
   });
 });