chore: update readme message

Extract the leaderboard into a generic, backend-agnostic package and add
rolling Today/Week/Month/All-Time windows, a web component, and local-first
development against the Firestore emulator.

Package (leaderboard/):
- LeaderBoardService: backend-agnostic core via a storage-adapter seam, with
  Firebase and Supabase adapters (Supabase client injected, no added dep)
- Rolling time windows (last 24h / 7d / 30d) with hover tooltips; top-N by score
- <cozy-leaderboard> web component built on web-component-base: compose the UI
  in HTML, configure the backend once in JS
- Every user-facing string is configurable (labels, tooltips, empty/loading/
  error messages, anonymous name) so i18n lives in the app; README + CONFIGURATION

App (mnswpr.com):
- Compose the board declaratively in index.html via <cozy-leaderboard>
- Nickname + randomized greeting bar; score submission through the element
- Legends: the current all-time leaders frozen into a static /legends page
- Firebase config and leaderboard namespace via Vite env vars; emulator-first
  local dev (VITE_FIRESTORE_EMULATOR)

Firebase schema-as-code:
- firebase.json, .firebaserc, firestore.rules (public reads, create-only scores,
  no client updates/deletes, namespace-generalized), empty indexes (rolling
  windows need none)
- prod (mw-*) vs dev/test (mw-test-*) separation by collection namespace
- emulator config, seed script, and docs (firebase-leaderboards.md,
  leaderboard-env-migration.md, AYO.md)

Utils/tests: UTC date-bucket helper (retained as metadata) with Vitest coverage.

Reviewed-on: https://git.ayo.run/ayo/mnswpr/pulls/1
Co-authored-by: Ayo <ayo@ayco.io>
Co-committed-by: Ayo <ayo@ayco.io>

README.md

@@ -1,3 +1,7 @@
+> [!IMPORTANT]
+> **mnswpr has a new home.** Development now happens in the **Cozy Games** monorepo:
+> **[git.ayo.run/ayo/cozy-games](https://git.ayo.run/ayo/cozy-games)**.
+
 # Play Minesweeper Online for Free
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