feat: Enhanced DebugWizard with folder selection and tree view

New features:
- Three input modes: Individual Files, Select Folder, Paste Code
- Folder selection support using webkitdirectory (Chrome/Edge/Safari)
- Tree view display of selected files organized by directory
- Collapsible directory groups
- Smart filtering: auto-excludes node_modules, .git, build, dist, images
- Upload statistics showing excluded files count
- Preserves relative paths from folder uploads

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

Co-Authored-By: Claude Opus 4.5 <[email protected]>

Author: 2 people