test: update tests for v2.28.5 behavior changes (v2.28.6) (#470)

- Update n8n-version tests: 'v' prefix now supported in version strings
- Update n8n-validation tests: empty settings now return minimal defaults
  { executionOrder: 'v1' } instead of {} to avoid API rejection (Issue #431)

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

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

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

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

@@ -55,7 +55,16 @@ describe('n8n-version', () => {
       expect(parseVersion('invalid')).toBeNull();
       expect(parseVersion('')).toBeNull();
       expect(parseVersion('1.2')).toBeNull();
-      expect(parseVersion('v1.2.3')).toBeNull(); // No 'v' prefix support
+    });
+
+    it('should handle v prefix in version strings', () => {
+      const result = parseVersion('v1.2.3');
+      expect(result).toEqual({
+        version: 'v1.2.3',
+        major: 1,
+        minor: 2,
+        patch: 3,
+      });
     });
   });