fix(gitflow): push hook names itself in its failure message (post-merge said post-commit)

.githooks/post-merge

@@ -1,5 +1,6 @@
 #!/bin/sh
 # gitflow post-merge — generated by gitflow_init. Do not hand-edit.
+hook=post-merge
 # Pushes every commit as it lands (BDR-095): a remote only backs up what it
 # holds. Never fails the commit: no origin / offline / refused → warning only.
 # Opt out for one command with GITFLOW_NO_PUSH=1 (throwaway repos, tests).
@@ -10,6 +11,6 @@ git remote get-url origin >/dev/null 2>&1 || exit 0
 br=$(git symbolic-ref --short -q HEAD 2>/dev/null) || exit 0   # detached HEAD — nothing to track
 if command -v timeout >/dev/null 2>&1; then t="timeout ${GITFLOW_PUSH_TIMEOUT:-30}"; else t=""; fi
 if $t git push -q -u --follow-tags origin "$br" >/dev/null 2>&1; then exit 0; fi
-echo "gitflow post-commit: push of '$br' FAILED — this commit exists only on this disk." >&2
+echo "gitflow $hook: push of '$br' FAILED — this commit exists only on this disk." >&2
 echo "  Push by hand: git push -u origin $br   (rejected as non-fast-forward? never force-push; ask first)" >&2
 exit 0