docs: retire the completed full-tree review plan

Every phase (P0-P7) is closed, so the plan file goes per its own exit criteria; history lives in git and the CHANGELOG. The roadmap's recommended order returns to queue-retries and then inbound-relay, and the order notes in both plans stop pointing at the deleted file, as does the 1.2.5 changelog entry (same treatment as logrotate-mode.md).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs/plans/queue-retries.md

@@ -3,8 +3,7 @@
 **Status:** agreed  
 **Date:** 2026-08-13  
 **Version:** patch; no schema, no configuration surface.  
-**Order:** small panel item; does not wait on inbound-relay. May follow or
-interleave with remaining [code-review.md](code-review.md) work after P0.
+**Order:** small panel item; does not wait on inbound-relay.
 
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