chore: bump version to 0.3.0

feat(shell): real terminal with xterm.js + PTY over WebSocket

Replace fake shell input with a full PTY-backed terminal using xterm.js.
Apps like btop, vim, htop now work. AI chat panel is always visible.

Backend:
- Add WebSocket handler /api/ws/terminal with creack/pty
- Allocate real pseudo-terminal with TERM=xterm-256color
- Bidirectional I/O + dynamic resize via pty.Setsize
- Skip JSON headers on /api/ws/* paths for WebSocket upgrade

Frontend:
- Integrate xterm.js with FitAddon and WebLinksAddon
- Cyberpunk color theme matching app design
- ResizeObserver for automatic terminal resizing
- AI assistant panel always visible (340px, no toggle)
- Connection status indicator (green/red dot)

Dependencies:
- Go: github.com/gorilla/websocket, github.com/creack/pty/v2
- npm: @xterm/xterm, @xterm/addon-fit, @xterm/addon-web-links

💘 Generated with Crush

Assisted-by: GLM-5.1 via Crush <crush@charm.land>

go.sum

@@ -44,10 +44,14 @@ github.com/clipperhouse/uax29/v2 v2.5.0 h1:x7T0T4eTHDONxFJsL94uKNKPHrclyFI0lm7+w
 github.com/clipperhouse/uax29/v2 v2.5.0/go.mod h1:Wn1g7MK6OoeDT0vL+Q0SQLDz/KpfsVRgg6W7ihQeh4g=
 github.com/creack/pty v1.1.24 h1:bJrF4RRfyJnbTJqzRLHzcGaZK1NeM5kTC9jGgovnR1s=
 github.com/creack/pty v1.1.24/go.mod h1:08sCNb52WyoAwi2QDyzUCTgcvVFhUzewun7wtTfvcwE=
+github.com/creack/pty/v2 v2.0.1 h1:RDY1VY5b+7m2mfPsugucOYPIxMp+xal5ZheSyVzUA+k=
+github.com/creack/pty/v2 v2.0.1/go.mod h1:2dSssKp3b86qYEMwA/FPwc3ff+kYpDdQI8osU8J7gxQ=
 github.com/dustin/go-humanize v1.0.1 h1:GzkhY7T5VNhEkwH0PVJgjz+fX1rhBrR7pRT3mDkpeCY=
 github.com/dustin/go-humanize v1.0.1/go.mod h1:Mu1zIs6XwVuF/gI1OepvI0qD18qycQx+mFykh5fBlto=
 github.com/erikgeiser/coninput v0.0.0-20211004153227-1c3628e74d0f h1:Y/CXytFA4m6baUTXGLOoWe4PQhGxaX0KpnayAqC48p4=
 github.com/erikgeiser/coninput v0.0.0-20211004153227-1c3628e74d0f/go.mod h1:vw97MGsxSvLiUE2X8qFplwetxpGLQrlU1Q9AUEIzCaM=
+github.com/gorilla/websocket v1.5.3 h1:saDtZ6Pbx/0u+bgYQ3q96pZgCzfhKXGPqt7kZ72aNNg=
+github.com/gorilla/websocket v1.5.3/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
 github.com/lucasb-eyer/go-colorful v1.3.0 h1:2/yBRLdWBZKrf7gB40FoiKfAWYQ0lqNcbuQwVHXptag=
 github.com/lucasb-eyer/go-colorful v1.3.0/go.mod h1:R4dSotOR9KMtayYi1e77YzuveK+i7ruzyGqttikkLy0=
 github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWEY=