* feat: add inline image and video rendering in terminal UI
Use sharp to render images as half-block character grids directly
in the terminal when media tool results are displayed, with ffmpeg
fallback for video thumbnail extraction.
* feat: auto-open generated media in OS viewer instead of inline rendering
Replace pixelated half-block terminal image rendering with native OS
viewer (`open` on macOS, `xdg-open` on Linux). Generated images and
videos now open automatically in full quality. Remove sharp dependency
and inline rendering utilities.
* bump version
* fix: use execFile instead of exec to prevent shell injection
* fix: remove auto-open from MediaToolResultView, keep only in MediaAutoOpenView