Let the admin choose one of eight colour profiles

Indigo (the default), Blue, Teal, Green, Amber, Rose and Violet in the
Vibrant style and Graphite in the Neutral style are generated from
config into the stylesheet. Admin settings opens with a colour profile
card: a swatch previews the profile on the page, and Save Settings
stores it as color_profile, which AppServiceProvider hands to the
package's resolver, so every page, mail and error page wears it. An
unknown profile is refused, and a saved one that disappears falls back
to indigo.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01V9NnLxnPp8vaaurb3Z1MFy

README.md

@@ -27,6 +27,7 @@ A simple, self-hosted file sharing solution built with Laravel. Upload files, ge
 - **Admin Dashboard** — View, manage, and delete all shares
 - **Admin Settings** — Configure upload limits, storage quotas, branding, and more
 - **Site Branding** — Custom logo, title, and description
+- **Colour Profiles** — Eight Material 3 colour profiles (Indigo, Blue, Teal, Green, Amber, Rose, Violet, Graphite); the admin picks one for every page, mail and error page
 - **System Password** — Optional global password gate to restrict upload access
 - **User Authentication** — Login, password reset, email verification
 - **Two-Factor Authentication** — TOTP-based 2FA via Laravel Fortify