feat: remove unnecessary 5-operation limit from n8n_update_partial_workflow

The 5-operation limit was overly conservative and unnecessary. Analysis showed:
- Workflow is cloned before modifications (no original mutation)
- All operations validated before any are applied (true atomicity)
- First error causes immediate return (no partial state possible)
- Two-pass processing handles dependencies correctly

Changes:
- Remove hard-coded 5-operation limit check from workflow-diff-engine.ts
- Update tool descriptions and documentation to reflect unlimited operations
- Add tests verifying 50 and 100+ operations work successfully
- Add example showing 26 operations in single request

The system already ensures complete transactional integrity regardless of
operation count. Bottleneck is workflow size, not operation count.

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

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

src/mcp/tools-n8n-manager.ts

@@ -160,7 +160,7 @@ export const n8nManagementTools: ToolDefinition[] = [
   },
   {
     name: 'n8n_update_partial_workflow',
-    description: `Update workflow incrementally with diff operations. Max 5 ops. Types: addNode, removeNode, updateNode, moveNode, enable/disableNode, addConnection, removeConnection, updateSettings, updateName, add/removeTag. See tools_documentation("n8n_update_partial_workflow", "full") for details.`,
+    description: `Update workflow incrementally with diff operations. Types: addNode, removeNode, updateNode, moveNode, enable/disableNode, addConnection, removeConnection, updateSettings, updateName, add/removeTag. See tools_documentation("n8n_update_partial_workflow", "full") for details.`,
     inputSchema: {
       type: 'object',
       additionalProperties: true,  // Allow any extra properties Claude Desktop might add