Play hub + Daily Word game (Phase 1 of the games feature)

A calm /play space — "after the brief, a small thing to enjoy." Framework-ready
for more games (Word Search next; zen/coloring later).

* Daily Word (5 letters / 6 guesses) + Long Word (6 / 7) — same Wordle mechanic,
  Upbeat Bytes flavor (no "Wordle" in the UI). Hopeful answers; after solving, a
  one-line "why this word matters."
* LLM proposes, code disposes: answers are picked deterministically by date-seed
  from a hand-curated hopeful pool that's pre-validated ⊆ the guess dictionary
  (always typeable), avoiding recent repeats; the LLM only adds the optional
  "why" (with fallback). daily_puzzles(date, game, variant, payload) stores them
  so everyone gets the same daily; the cycle pre-generates with the "why".
* Bundled guess dictionaries (words-5/6.json, ~12.6k/22.4k) for client-side guess
  validation — never the LLM. Answer lightly obfuscated (base64) in the payload.
* Private, gentle stats (played/solved/streak, guess distribution); spoiler-free
  emoji-grid share. No leaderboard, no timer, no streak-loss drama.
* Play in the bottom nav (replacing Browse, still on the lane rail) + the header.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

frontend/package.json

@@ -12,6 +12,7 @@
     "@sveltejs/adapter-static": "^3.0.6",
     "@sveltejs/kit": "^2.8.0",
     "@sveltejs/vite-plugin-svelte": "^5.0.0",
+    "an-array-of-english-words": "^2.0.0",
     "svelte": "^5.1.0",
     "vite": "^6.0.0"
   }