EventCluster's same-year header re-implemented EventPill's glyph circle,
serif title, provenance subtitle, and the curator edit anchor near-
verbatim — the third copy of that markup. They now share a single
EventHeader component (glyph via GlyphLabel, title, `{date} · provenance`
subtitle, optional sr-only letter count, and the canEditEvent-gated edit
pencil); EventPill keeps only its pill border, EventCluster only its card
chrome. Second half of review finding #5 (Architect-1). No behavior
change — EventPill/EventCluster/YearBand/TimelineView specs stay green.
Refs #850
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
