Session-ended event beads were accumulating without being processed.
Modified costs.go to auto-close these events immediately after creation
since they are informational audit events. The event data is preserved
in the closed bead and remains queryable.
Also bulk-closed 83 existing stale session-ended events.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>