messages edit is accepted but get/history still show the original kind 9

[avivsinai]

Repro (stock CLI v0.5.2)

1. buzz messages send --channel <uuid> --content 'edit-probe' --broadcast → accepted, kind 9 event id E.
2. buzz messages edit --event E --content 'edit-probe-UPDATED' → accepted, kind 40003 event id F with tags h + e(E).
3. buzz messages get --channel <uuid> still returns the original kind 9 content for E.
4. buzz messages thread --channel <uuid> --event E shows both F (40003, new content) and E (kind 9, old content).

Live sample against a v0.5.2 relay (2026-08-20):

• send 5bd313b459b3886657bcf18cb931aa6baa242be78ccb11670effb2fa4b25f9bf kind 9 edit-probe 141148
• edit accepted f31fce0838880bd639ad68c13ea7d52275f66a4b3fb8325baaea97a929dd9cc2 kind 40003
• messages get still showed the original kind 9

Expected

Read paths (messages get / history) apply the latest kind 40003 so callers see the edited content.

Impact

Bridges and agents cannot verify edit round-trips. Slack-style edit mirroring into Buzz is invisible on get/history.