* chore: clean up repo root for faster README visibility
- Delete unused images (debug_orca.png, orca_3d.jpg, screenshot.png)
- Delete stale design docs from docs/
- Move tsconfig sub-configs, electron-builder config, and vitest config to config/
- Move file-drag.gif to docs/assets/ and design doc to docs/
- Update all path references in package.json, tsconfig.json, and moved configs
* fix: remove stale worktree dialog callback dependency
