DX Improvements: Bun support, multi-instance config, and terminal paste fix + Feat: Model selection

[PylotLight]

1. DX Improvements:

• Added bun build and dev scripts to package.json.
• Implemented a Bun packaging wrapper for Electron builds.

2. Application Configuration:

• Added "Allow multiple app instances" toggle in General Settings.
• Implemented persistence for this setting in ui-state.json.
• Added a synchronous boot-time check in main.ts to respect this setting before requesting the single-instance lock.
• Added PI_APP_ALLOW_MULTIPLE=1 environment variable as a forced override.

3. Bug Fixes:

• Fixed a bug where pasting into the embedded terminal duplicated the text.

4. Features:

• Model selection search filters in Settings.

[vercel]

@PylotLight is attempting to deploy a commit to the dev Team on Vercel.

A member of the Team first needs to authorize it.