838b5162bc
- Introduced `web-palette.ts` to implement the collab-web pink/purple brand identity for HTML exports. - Updated `generateThemeVars` to support a `palette` option, allowing users to choose between the brand-web aesthetic and a specific TUI theme. - Configured public exports and the share-viewer script to default to the brand-web palette rather than inheriting the user's terminal theme. - Refactored `AgentSession.exportToHtml` to align with the new branding defaults while allowing for per-export theme overrides. - Adjusted `dark.json` background values to ensure better visual consistency across internal surfaces.