fix(ci): correct output.formats to map structure for golangci-lint v2

- Changed output.formats from array to map with 'default' key
- Fixes "expected a map, got 'slice'" error

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

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

Author: thc1006

.golangci.yml

@@ -27,4 +27,5 @@ issues:
 
 output:
   formats:
-    - format: colored-line-number
+    default:
+      format: colored-line-number