Word Search bug-fixes + Codex polish

Two reported bugs, same root cause: the fixed-cell grid overflowed its wrapper
on Large, so (a) the last column spilled past the border and (b) the pointer→cell
math drifted across the row, recording finds "off by a letter".
* Grid now uses 1fr columns with max-width = n·32px: the board grows with the
  grid and can never overflow (shrinks to fit a narrow phone instead).
* cellAt() accounts for the grid padding/border, so selection is exact edge-to-edge.
* restore() now validates each saved find against the CURRENT grid and drops any
  whose cells no longer spell the word — clears stale highlights if the day's
  puzzle changed.

Codex follow-ups:
* _ws_propose now requires >= large.count + 4 valid words before accepting an LLM
  proposal (else falls back to a curated theme), so a thin LLM result can't
  underfill Large. Added a thin-LLM fallback test.
* Cleaned Svelte warnings: removed the now-unused .gamecard.soon CSS, added an
  ARIA role/label to the grid, declared gridEl with $state. Build is warning-clean.
* Added a stale-load guard in WordSearchGame.load() so rapid size switches can't
  let an older request overwrite the newer selection.

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

tests/test_admin.py

@@ -336,3 +336,28 @@ def test_wordsearch_endpoint(tmp_path, monkeypatch):
     assert len(themes) == 1  # all sizes share the day's one theme
     # an unknown size falls back to med
     assert tc.get("/api/puzzle/wordsearch?variant=nope").json()["size"] == "med"
+
+
+def test_wordsearch_thin_llm_falls_back(tmp_path, monkeypatch):
+    from goodnews.db import connect, init_db
+    from goodnews import games
+
+    class FakeClient:
+        def __init__(self, text):
+            self.text = text
+
+        def chat_text(self, msg):
+            return self.text
+
+    c = connect(":memory:"); init_db(c)
+    # Thin proposal (only ~6 valid words) must be REJECTED so Large can't underfill.
+    thin = FakeClient("THEME: Thin Theme\nWORDS: ONE, TWO, FOUR, FIVE, SEVEN, EIGHT, THREE")
+    p = games.generate_wordsearch_puzzle(c, "2026-07-01", client=thin)
+    assert p["theme"] != "Thin Theme"  # fell back to a curated theme
+    large = games.wordsearch_response(c, "2026-07-01", "large")
+    assert len(large["words"]) == games.WS_TIERS["large"]["count"]  # still full
+
+    # A rich proposal (>= WS_MIN_ACCEPT valid words) is accepted.
+    rich = FakeClient("THEME: Rich Theme\nWORDS: " + ", ".join(chr(65 + i) * 5 for i in range(20)))
+    p2 = games.generate_wordsearch_puzzle(c, "2026-07-02", client=rich)
+    assert p2["theme"] == "Rich Theme" and len(p2["words"]) >= games.WS_MIN_ACCEPT