fix(settings): restore background swatch grid layout; verify N4 poll fix

- Add grow="Yes" to ChatBgGrid and SeasonalBgGrid containers so they
  expand to fill their flex parent — without it the Box shrank to one
  column (~76px wide) because folds Box defaults to display:flex and
  the wrapper is a flex-row with no explicit width.
- Mark N4 (PollContent) FIXED ✅ VERIFIED in LOTUS_BUGS.md after
  confirmed pass on default Cinny themes and Lotus TDS.
- Mark B1 and B4 PASS in LOTUS_TESTING.md.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

LOTUS_TESTING.md

@@ -126,7 +126,7 @@ This guards against a permanently-stuck "Loading…" call. Also covers the N96 b
 
 This was the actual bug: poll buttons used undefined CSS variables, so on the **default (non-Lotus-Terminal) themes** they rendered with invisible borders / no selected state.
 
-### B1. Poll renders on a default theme
+### B1. Poll renders on a default theme — ✅ PASS
 
 1. Switch to a **default Cinny theme** (Settings → Appearance — **not** Lotus Terminal / TDS). Test both a **dark** and a **light** theme.
 2. In any room, create a poll (composer → poll button): a **single-choice** poll with 3 options.
@@ -154,7 +154,7 @@ This was the actual bug: poll buttons used undefined CSS variables, so on the **
 - Indicators are **square checkboxes** (not circles); selected ones show a **✓** that's legible against the filled box.
 - You can select **several** options; each shows its own progress fill.
 
-### B4. Lotus Terminal theme regression
+### B4. Lotus Terminal theme regression — ✅ PASS
 
 1. Switch to **Lotus Terminal / TDS** theme and re-open a poll.
    **Expected:** still looks correct (the fix uses theme tokens, so the TDS accent should now drive it) — no worse than before.