chore: release v4.1.0

Breaking changes:
- OpenCode: Switched to native skills system (migration required)

Fixes:
- OpenCode: Fixed agent reset on session start (#226)
- OpenCode: Fixed Windows installation (#232)
- Claude Code: Fixed Windows hook execution for 2.1.x

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

RELEASE-NOTES.md

@@ -1,6 +1,6 @@
 # Superpowers Release Notes
 
-## Unreleased
+## v4.1.0 (2026-01-23)
 
 ### Breaking Changes