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>

goodnews/api.py

@@ -33,7 +33,8 @@ from fastapi.responses import HTMLResponse, RedirectResponse
 from fastapi.staticfiles import StaticFiles
 from pydantic import BaseModel
 
-from . import auth, email_send, feeds, oauth_google, queries, share, sources, summarize
+from . import auth, email_send, feeds, games, oauth_google, queries, share, sources, summarize
+from .localtime import local_today
 from .markup import reply_html_to_text, sanitize_reply_html
 from .db import connect
 from .filters import filter_articles, prefs_from_json
@@ -1422,6 +1423,13 @@ def create_app() -> FastAPI:
             items=[Article.from_row(r) for r in rows],
         )
 
+    @app.get("/api/puzzle/{game}")
+    def daily_puzzle(game: str, variant: str = Query("5")) -> dict:
+        if game != "word" or variant not in games.WORD_VARIANTS:
+            raise HTTPException(status_code=404, detail="no such puzzle")
+        with get_conn() as conn:
+            return games.word_puzzle_response(conn, local_today(), variant)
+
     @app.get("/api/since", response_model=FeedResponse)
     def feed_since(ts: str = Query(...), prefs: str | None = Query(None)) -> FeedResponse:
         # A calm welcome-back cue: accepted/non-dup/visible articles discovered