Three-step shrink:
1. > 600px pane: cluster sits in col 2 as 1 row of 6
2. 380-600px pane: cluster capped at 3-icon width so wrapping
stops at 3 + 3 (max 2 rows) — chips share width with the 2-row
cluster instead of multiplying into 3+ rows
3. < 380px pane: cluster snaps to absolute overlay with left-edge
box-shadow, still capped at 3-icon width so it's the same 2-row
shape but floating above the truncated chips
d95abaff1b