fix(ci): rename registry-stuck workflows to force fresh registration

governance.yml, secret-scanner.yml, mirror.yml, instant-sync.yml all show
name==path in the Actions workflow registry — the malformed-at-creation
cached state where every run dies at 0s (startup_failure) regardless of
current file content. Renaming forces fresh registration (verified estate
precedent: paint-type#38, 2026-06-01). Content unchanged.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: hyperpolymath