fix: add n8n 1.121 availableInMCP and callerPolicy settings support (v2.26.4) (#445)

* fix: add n8n 1.121 availableInMCP and callerPolicy settings support (v2.26.4)

n8n 1.121 introduced a new workflow setting `availableInMCP` (boolean)
that controls whether a workflow is "Available in MCP". The sanitization
whitelist was missing this field, causing it to be silently stripped
during workflow updates.

Changes:
- Added `availableInMCP` to Zod schema in workflowSettingsSchema
- Added `availableInMCP` and `callerPolicy` to safeSettingsProperties whitelist
- Both settings are now preserved during workflow updates
- Settings can be toggled via updateSettings operation

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

Co-Authored-By: Claude <noreply@anthropic.com>
Conceived by Romuald Członkowski - www.aiadvisors.pl/en

* test: update tests for callerPolicy and availableInMCP whitelist changes

Updated 5 tests in n8n-validation.test.ts that expected callerPolicy
to be filtered out. Since callerPolicy and availableInMCP are now
whitelisted (n8n 1.121+), the tests now verify these settings are
preserved during workflow updates.

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

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

---------

Co-authored-by: Claude <noreply@anthropic.com>

src/services/n8n-validation.ts

@@ -62,6 +62,7 @@ export const workflowSettingsSchema = z.object({
   executionTimeout: z.number().optional(),
   errorWorkflow: z.string().optional(),
   callerPolicy: z.enum(['any', 'workflowsFromSameOwner', 'workflowsFromAList']).optional(),
+  availableInMCP: z.boolean().optional(),
 });
 
 // Default settings for workflow creation
@@ -181,7 +182,9 @@ export function cleanWorkflowForUpdate(workflow: Workflow): Partial<Workflow> {
     'executionTimeout',
     'errorWorkflow',
     'timezone',
-    'executionOrder'
+    'executionOrder',
+    'callerPolicy',
+    'availableInMCP',
   ];
 
   if (cleanedWorkflow.settings && typeof cleanedWorkflow.settings === 'object') {