Add .gitignore for 007-iFrameURL sample

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

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

Author: miquelgall

samples/007-iFrameURL/.gitignore

@@ -0,0 +1,11 @@
+credentials*.json
+**/credentials.json
+.DS_Store
+**/.DS_Store
+**/node_modules
+**/dist
+**/build
+**/coverage
+**/temp
+**/.claude/**
+**/CLAUDE.md