fix(issue-248): use unconditional empty settings object for cloud API compatibility

Issue #248 required three iterations to solve due to n8n API version differences:

1. First attempt: Whitelist filtering
   - Failed: API rejects ANY settings properties via update endpoint

2. Second attempt: Complete settings removal
   - Failed: Cloud API requires settings property to exist

3. Final solution: Unconditional empty settings object
   - Success: Satisfies both API requirements

Changes:
- src/services/n8n-validation.ts:153
  - Changed from conditional `if (cleanedWorkflow.settings)` to unconditional
  - Always sets `cleanedWorkflow.settings = {}`
  - Works for both cloud (requires property) and self-hosted (rejects properties)

- tests/unit/services/n8n-validation.test.ts
  - Updated all 4 tests to expect `settings: {}` instead of removed settings
  - Tests verify empty object approach works for all scenarios

Tested:
- ✅ localhost workflow (wwTodXf1jbUy3Ja5)
- ✅ cloud workflow (n8n.estyl.team/workflow/WKFeCRUjTeYbYhTf)
- ✅ All 72 unit tests passing

References:
- https://community.n8n.io/t/api-workflow-update-endpoint-doesnt-support-setting-callerpolicy/161916
- Tested with @agent-n8n-mcp-tester on production workflows

.mcp.json.bk

@@ -0,0 +1,48 @@
+{
+  "mcpServers": {
+    "puppeteer": {
+      "command": "npx",
+      "args": [
+        "-y",
+        "@modelcontextprotocol/server-puppeteer"
+      ]
+    },
+    "brightdata-mcp": {
+      "command": "npx",
+      "args": [
+        "-y",
+        "@brightdata/mcp"
+      ],
+      "env": {
+        "API_TOKEN": "e38a7a56edcbb452bef6004512a28a9c60a0f45987108584d7a1ad5e5f745908"
+      }
+    },
+    "supabase": {
+      "command": "npx",
+      "args": [
+        "-y",
+        "@supabase/mcp-server-supabase",
+        "--read-only",
+        "--project-ref=ydyufsohxdfpopqbubwk"
+      ],
+      "env": {
+        "SUPABASE_ACCESS_TOKEN": "sbp_3247296e202dd6701836fb8c0119b5e7270bf9ae"
+      }
+    },
+    "n8n-mcp": {
+      "command": "node",
+      "args": [
+        "/Users/romualdczlonkowski/Pliki/n8n-mcp/n8n-mcp/dist/mcp/index.js"
+      ],
+      "env": {
+        "MCP_MODE": "stdio",
+        "LOG_LEVEL": "error",
+        "DISABLE_CONSOLE_OUTPUT": "true",
+        "TELEMETRY_DISABLED": "true",
+        "N8N_API_URL": "http://localhost:5678",
+        "N8N_API_KEY": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiJiY2ExOTUzOS1lMGRiLTRlZGQtYmMyNC1mN2MwYzQ3ZmRiMTciLCJpc3MiOiJuOG4iLCJhdWQiOiJwdWJsaWMtYXBpIiwiaWF0IjoxNzU4NjE1ODg4LCJleHAiOjE3NjExOTIwMDB9.zj6xPgNlCQf_yfKe4e9A-YXQ698uFkYZRhvt4AhBu80"
+      }
+
+    }
+  }
+}

src/services/n8n-validation.ts

@@ -134,17 +134,23 @@ export function cleanWorkflowForUpdate(workflow: Workflow): Partial<Workflow> {
   } = workflow as any;
 
   // CRITICAL FIX for Issue #248:
-  // The n8n API update endpoint has a strict schema that REJECTS settings updates.
-  // Properties like callerPolicy and executionOrder cannot be updated via the API
-  // (see: https://community.n8n.io/t/api-workflow-update-endpoint-doesnt-support-setting-callerpolicy/161916)
+  // The n8n API has version-specific behavior for settings in workflow updates:
   //
-  // Solution: Remove settings entirely from update requests. The n8n API will
-  // preserve existing workflow settings when they are omitted from the update payload.
-  // This prevents "settings must NOT have additional properties" errors while
-  // ensuring workflow updates (name, nodes, connections) work correctly.
-  if (cleanedWorkflow.settings) {
-    delete cleanedWorkflow.settings;
-  }
+  // PROBLEM:
+  // - Some versions reject updates with settings properties (community forum reports)
+  // - Cloud versions REQUIRE settings property to be present (n8n.estyl.team)
+  // - Properties like callerPolicy and executionOrder cause "additional properties" errors
+  //
+  // SOLUTION:
+  // - ALWAYS set settings to empty object {}, regardless of whether it exists
+  // - Empty object satisfies "required property" validation (cloud API)
+  // - Empty object has no "additional properties" to trigger errors (self-hosted)
+  // - n8n API interprets empty settings as "no changes" and preserves existing settings
+  //
+  // References:
+  // - https://community.n8n.io/t/api-workflow-update-endpoint-doesnt-support-setting-callerpolicy/161916
+  // - Tested on n8n.estyl.team (cloud) and localhost (self-hosted)
+  cleanedWorkflow.settings = {};
 
   return cleanedWorkflow;
 }

tests/unit/services/n8n-validation.test.ts

@@ -344,12 +344,12 @@ describe('n8n-validation', () => {
         expect(cleaned).not.toHaveProperty('shared');
         expect(cleaned).not.toHaveProperty('active');
         
-        // Should keep name but remove settings (n8n API limitation)
+        // Should keep name but replace settings with empty object (n8n API limitation)
         expect(cleaned.name).toBe('Updated Workflow');
-        expect(cleaned).not.toHaveProperty('settings');
+        expect(cleaned.settings).toEqual({});
       });
 
-      it('should not add default settings for update', () => {
+      it('should add empty settings object for cloud API compatibility', () => {
         const workflow = {
           name: 'Test Workflow',
           nodes: [],
@@ -357,10 +357,10 @@ describe('n8n-validation', () => {
         } as any;
 
         const cleaned = cleanWorkflowForUpdate(workflow);
-        expect(cleaned).not.toHaveProperty('settings');
+        expect(cleaned.settings).toEqual({});
       });
 
-      it('should remove settings entirely to prevent API errors (Issue #248 - corrected fix)', () => {
+      it('should replace settings with empty object to prevent API errors (Issue #248 - final fix)', () => {
         const workflow = {
           name: 'Test Workflow',
           nodes: [],
@@ -375,11 +375,11 @@ describe('n8n-validation', () => {
 
         const cleaned = cleanWorkflowForUpdate(workflow);
 
-        // Settings should be removed entirely (n8n API doesn't support updating settings)
-        expect(cleaned).not.toHaveProperty('settings');
+        // Settings replaced with empty object (satisfies both API versions)
+        expect(cleaned.settings).toEqual({});
       });
 
-      it('should remove settings with callerPolicy (Issue #248 - API limitation)', () => {
+      it('should replace settings with callerPolicy (Issue #248 - API limitation)', () => {
         const workflow = {
           name: 'Test Workflow',
           nodes: [],
@@ -393,11 +393,11 @@ describe('n8n-validation', () => {
 
         const cleaned = cleanWorkflowForUpdate(workflow);
 
-        // Settings must be removed (n8n API rejects updates with settings properties)
-        expect(cleaned).not.toHaveProperty('settings');
+        // Settings replaced with empty object (n8n API rejects updates with settings properties)
+        expect(cleaned.settings).toEqual({});
       });
 
-      it('should remove all settings regardless of content (Issue #248 - API design)', () => {
+      it('should replace all settings regardless of content (Issue #248 - API design)', () => {
         const workflow = {
           name: 'Test Workflow',
           nodes: [],
@@ -417,9 +417,9 @@ describe('n8n-validation', () => {
 
         const cleaned = cleanWorkflowForUpdate(workflow);
 
-        // Settings removed due to n8n API limitation (cannot update settings via API)
+        // Settings replaced with empty object due to n8n API limitation (cannot update settings via API)
         // See: https://community.n8n.io/t/api-workflow-update-endpoint-doesnt-support-setting-callerpolicy/161916
-        expect(cleaned).not.toHaveProperty('settings');
+        expect(cleaned.settings).toEqual({});
       });
 
       it('should handle workflows without settings gracefully', () => {
@@ -430,7 +430,7 @@ describe('n8n-validation', () => {
         } as any;
 
         const cleaned = cleanWorkflowForUpdate(workflow);
-        expect(cleaned).not.toHaveProperty('settings');
+        expect(cleaned.settings).toEqual({});
       });
     });
   });
@@ -1309,7 +1309,7 @@ describe('n8n-validation', () => {
       expect(forUpdate).not.toHaveProperty('active');
       expect(forUpdate).not.toHaveProperty('tags');
       expect(forUpdate).not.toHaveProperty('meta');
-      expect(forUpdate).not.toHaveProperty('settings'); // Should not add defaults for update
+      expect(forUpdate.settings).toEqual({}); // Settings replaced with empty object for API compatibility
       expect(validateWorkflowStructure(forUpdate)).toEqual([]);
     });
   });