v0.57.3: Task tool streaming, image pasting, and skills improvements

New features

- Task tool live streaming - Real-time subagent tool progress display and Execute tool output streaming in web and Factory App surfaces
- Image pasting - Paste images directly into the chat composer (Factory App)
- .agent skills folders - Skills can now be loaded from .agent folders in your project for custom skill support

Improvements

- Skills filtering - Skills are now filtered by model invocability so only relevant skills appear in the Skill tool

Bug fixes

- File suggestion UX - Trailing space now added after file suggestion selection for smoother typing