- .tile-bell: inline-flex badge (min-width:16px height:16px) so it's a
circle for single digits, pill for '9+'; was display:inline so
width/height were ignored → oval shape
- .tile-bell color: #0D1117 (dark on amber) — was inheriting muted gray
from .tile-meta, making count illegible
- formatTimestamp(null): return '' instead of em-dash '—' which rendered
as a confusing glyph in the tile meta area