Add Hepburn skin with full light/dark palette derived from the
Hepburn TUI theme. Brand color #c6246a with pink-magenta accents.
- Light: soft pink surfaces (#fff3f7 / #fbe4ed)
- Dark: deep aubergine (#110a0f / #1e0f19)
- Accent: #d44a7a (light) / #f278ad (dark)
- Styled: send button, new chat button, tool cards, session indicator
Also fix settings panel skin picker to prioritize localStorage
over server defaults, so newly selected skins reflect correctly
in the dropdown.
75fdadd477
