- .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
Previously the <pre> snapshot floated to the top of .tile-body — when
content overflowed, the oldest lines showed and newest were clipped.
Now .tile-body pre is position:absolute;bottom:0 so overflow clips
from the top and the lower-left corner (newest content) is always shown.