chore(meta): update changelog

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

CHANGELOG.md

@@ -16,6 +16,10 @@ Format based on [Keep a Changelog](https://keepachangelog.com/).
 - Entity renderer migrated from ColorRect placeholders to Sprite2D with D-019 angle sprites — self_modulate for D-033 tinting, 8→4 octant direction mapping, feet-anchored y-sort (#540)
 
 ### Changed
+- `/sprint-status` delegates to haiku subagent — keeps sweep JSON, template read, and PR list out of main context window
+- `sprint sweep` JSON trimmed — removed unused fields (`ok`, `sprint.status`, `priority`, `ticket_id`), shortened issue detail strings
+- Sprint status output template condensed — rendering rules moved to skill definition, bookkeeping table simplified to 2 columns
+- Model selection documented in CLAUDE.md — `/model sonnet[1m]` and `/model opus[1m]` for 1M context sessions
 - Sprint 17 briefings updated with workshop results — server (14 tickets), copy (2 tickets), client (2), visual (1)
 - Q-024 (gossip timing), Q-025 (KG memory), Q-026 (contradiction detection) closed
 - Sprint 16 closed (8/8 done)