docs(catalog): repo-mailbox stat line 978 -> 1006 selftest checks

Mirrors repo-mailbox's own badge (selftest_checks-1006 at 4fd1955, the
0.36.0 release commit). release-plugin.mjs refused the 0.36.0 dry-run on
the stale stat line before tagging; it now passes that pre-flight and
stops only at the not-yet-minted v0.36.0 tag.

check-versions shows 1 ERROR on repo-mailbox until the release moves the
ref: the gate reads the badge at the pinned v0.35.0 (978). That finding
is kind=stat for the plugin being released, which preflightErrors()
exempts - measured: preflightErrors(gate, 'repo-mailbox') -> [].

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

README.md

@@ -232,7 +232,7 @@ A local mailbox for coordination between Claude Code sessions in different repos
 - **`route`** — turns four scored traits of the next task into a model/effort row from a closed six-row rubric, with a pasteable startup command and a one-row-cheaper fallback
 - **`dispatch`** — hands work to a session in another repo as a complete, verified startup command: the prompt written to a file, model and effort derived from the rubric, output form chosen by whether the target repo already has a terminal pane
 
-1 hook · 4 skills · 8 CLI scripts · 978 selftest checks · [Full documentation →](https://git.fromaitochitta.com/open/repo-mailbox)
+1 hook · 4 skills · 8 CLI scripts · 1006 selftest checks · [Full documentation →](https://git.fromaitochitta.com/open/repo-mailbox)
 
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