release: v2.3.0 — reopen trigger, short UUID prefix, inline guidance responses

[jpicklyk]

Summary

• Added reopen trigger to advance_item — reopens terminal items back to queue
• Added short UUID prefix resolution to query_items get — resolve items by 4+ hex chars
• Added guidancePointer and noteProgress to advance_item and manage_notes responses — eliminates N-1 get_context round-trips
• Added role guard to manage_items update — rejects direct role changes
• Extracted shared PhaseNoteContext computation across gate-check call sites
• Refined agent-owned-phase protocol in plugin hook and skills

Version

Release type: both

• Server: 2.2.0 -> 2.3.0 (minor)
• Plugin: 2.5.1 -> 2.5.2 (patch)

Prepared with /prepare-release