chore: ignore tdd build artifacts

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: Snider

.gitignore

@@ -2,3 +2,8 @@
 build/wails2/build/bin
 build/wails2/node_modules
 build/wails2/frontend/dist
+
+# TDD test artifacts
+tdd/.build/
+tdd/**/node_modules/
+tdd/tdd/