2026-03-25: Topic Evolution Port

What Changed

• ported Topic Evolution into src/server/plugins/ports/topic-evolution.ts
• added a thin GET /api/v1/plugins/topic-evolution route
• added the codex-side /app/evolution page
• reused the new shared vector/clustering helper instead of duplicating embedding math again
• added unit coverage for period building and shift detection

Why It Matters

This confirms the new shared vector layer is not a one-off abstraction for Knowledge Gaps.

It now powers multiple codex analysis ports and makes later convergence work simpler for:

• mind-map-generator
• sentiment-timeline
• any later feature that needs topic clustering over embedded memories

Remaining Gaps

• the codex page is a focused version of the evolution UI, not the full frain visualization surface yet
• Sentiment Timeline and Mind Map Generator are the next natural ports to reuse this shared foundation