chore: re-verify dark-mode category chips and 58mm printing on 3.13.0 #1349

Parent: #830 (chat leftovers). Verify and close. Verified against main @ 8e39053.

Two September reports look fixed or unchanged in code but were never re-checked on a current build.

1. Dark mode: category text invisible (9 Sep)

• Likely fixed by fix(frontend): improve dark-mode contrast across dashboard and POS #691 (3.11.0). POS category chips use theme-aware dark: classes (frontend/src/components/pos/ProductGrid.tsx ~L148-160).
• Check on 3.13.0 in dark mode, including custom category colors. If fine, close this item. If not, add an e2e contrast check.

2. 58mm printer widths

• Profiles exist: generic-escpos-58 (32 columns, 384-dot raster) and 58mm-36 / cols-NN overrides (main/printers/profiles.ts ~L98-118, L168; docs/printers.md). Nothing has changed since the report.
• Print a receipt, a KOT and a delivery slip on a 58mm printer with the generic-escpos-58 profile. Check for wrapping or cut-off totals. If broken, attach a photo, and fix it via tests/receipt-column-oracle.test.ts (golden).