* feat(web-shell): support custom Hex session group colors
* docs(web-shell): add custom group color screenshot
* fix(web-shell): address custom Hex color review feedback
* fix(web-shell): validate group presets against daemon catalog and auto-prefix Hex input
Review follow-ups for the custom Hex group color editor:
- Validate the preset branch against the daemon-provided color catalog
instead of the hardcoded palette, so future preset additions stay
selectable in the editor.
- Auto-prefix bare values with '#' in the Hex field so pasted bare Hex
validates, and free text can no longer collide with a preset name and
silently flip the select out of Custom mode.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
* fix(web-shell): cap custom Hex input length
---------
Co-authored-by: qwen-code-dev-bot <qwen-code-dev-bot@users.noreply.github.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
