gitignore every mutants output folder

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GWVo7x3UHw5kwCUaWxiejX

.gitignore

@@ -3,9 +3,6 @@
 .DS_Store
 site/dist/
 .netlify/
+# cargo-mutants output (just mutants*)
 /mutants.out*/
-/mutants-store/
+/mutants-*/
-/mutants-import/
-/mutants-config/
-/mutants-mcp/
-/mutants-gui/