feat: integrate Claude binary and improve build workflow

- Add predev script to build executables before starting dev server
- Configure Tauri to include claude-code as external binary
- Reorganize Tauri command handlers with clear section comments for better maintainability
- Add bun build temporary files to .gitignore

These changes enable proper Claude binary integration and ensure executables are built before development.

Fixes #136

package.json

@@ -4,6 +4,7 @@
   "version": "0.1.0",
   "type": "module",
   "scripts": {
+    "predev": "bun run build:executables:current",
     "dev": "vite",
     "build": "tsc && vite build",
     "prebuild": "bun run build:executables:current",