Rebrand as Playlink with a new sunset theme

- Name: Playlink in the UI, page title, footer, messages and README
  (file names like playlink.db and .playlink-trash are unchanged).
- Theme: plum-black surfaces with a coral-to-pink accent, a soft glow
  behind the page, gradient primary buttons, toggles and progress bars,
  accent focus rings and slim scrollbars.
- New logo (beamed notes on the brand gradient) and a Play/link wordmark.
- Inter variable font, bundled so it works under the strict CSP.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

web/package.json

@@ -9,6 +9,7 @@
     "typecheck": "tsc -b"
   },
   "dependencies": {
+    "@fontsource-variable/inter": "^5.3.0",
     "@tanstack/react-query": "^5.103.2",
     "lucide-react": "^1.47.0",
     "react": "^19.3.0",