rescope vrg-reword away from the dead commit-message-fidelity check (#1888)
Post-#1872 stale-code sweep. vrg-reword's module docstring and CLAUDE.md description framed it as the path to fix a commit-message-fidelity audit failure; that judgment check is gone with the dual-agent loop. Reframe it as a general-purpose, bounded, agent-safe branch-local commit-message reword (the only safe path with raw interactive rebase blocked repo-wide). Tool and behavior unchanged. vrg-pr-fix-body assessed and kept unchanged (documented general tool; its audit mention is the retained identity guard). Ref #1887