fix: resolve partial update validation/execution discrepancy (issue #45)

- Remove default settings logic from cleanWorkflowForUpdate that was causing
  "settings must NOT have additional properties" error
- The function now only removes read-only fields without adding any properties
- Add comprehensive test coverage in test-issue-45-fix.ts
- Add documentation explaining the difference between create and update functions
- Bump version to 2.7.14

This fixes the issue where n8n_update_partial_workflow would pass validation
but fail during execution when workflows didn't have settings defined.

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

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

src/services/n8n-validation.ts

@@ -93,6 +93,19 @@ export function cleanWorkflowForCreate(workflow: Partial<Workflow>): Partial<Wor
   return cleanedWorkflow;
 }
 
+/**
+ * Clean workflow data for update operations.
+ * 
+ * This function removes read-only and computed fields that should not be sent
+ * in API update requests. It does NOT add any default values or new fields.
+ * 
+ * Note: Unlike cleanWorkflowForCreate, this function does not add default settings.
+ * The n8n API will reject update requests that include properties not present in
+ * the original workflow ("settings must NOT have additional properties" error).
+ * 
+ * @param workflow - The workflow object to clean
+ * @returns A cleaned partial workflow suitable for API updates
+ */
 export function cleanWorkflowForUpdate(workflow: Workflow): Partial<Workflow> {
   const {
     // Remove read-only/computed fields
@@ -116,11 +129,6 @@ export function cleanWorkflowForUpdate(workflow: Workflow): Partial<Workflow> {
     ...cleanedWorkflow
   } = workflow as any;
 
-  // Ensure settings are present
-  if (!cleanedWorkflow.settings) {
-    cleanedWorkflow.settings = defaultWorkflowSettings;
-  }
-
   return cleanedWorkflow;
 }