fix(hooks): correct the false deferral claim in check-regen-pending.mjs and .githooks/pre-commit (#14545)

Both sibling copies of the false claim corrected in os-regen-merge.sh by
#14154 survived: the hook's refuse-stale message and the pre-commit header
still said this hook records the sanctioned landing sequence's step-3
commit as a deferral. It does not — step 1's merge auto-commits with no
hook run at all (git skips pre-commit for a merge it completes itself), so
the marker is untouched going into step 3, whose commit is an ordinary one
this hook refuses on purpose. That refusal is the designed collection
point, not a deferral.

The deferral mode (#8047) is real, but applies only to a merge commit
finished BY HAND with MERGE_HEAD present at commit time — a conflicted
merge an operator resolves and finishes with `git commit`. Both texts now
state that precisely, mirroring the reference wording already correct in
scripts/pm/os-regen-merge.sh:110-115.

Fixes #14470

Co-authored-by: Claude <noreply@anthropic.com>

Author: baozhoutao

.githooks/pre-commit

@@ -6,12 +6,18 @@
 # exits before doing any work, which is every commit that did not just merge a
 # generator-owned artifact (#4675).
 #
-# One commit is exempt, and only one: the MERGE commit itself, which the
-# sanctioned landing sequence (`scripts/pm/os-regen-merge.sh`, step 3) commits
-# BEFORE regenerating, so that "what main brought" stays readable apart from
-# "what the change produces". That commit records a deferral instead of being
-# refused; the immediately following commit must discharge it, and
-# `.githooks/pre-push` refuses the push if none ever does (#8047).
+# One commit is exempt, and only one: a MERGE commit finished BY HAND, with
+# `MERGE_HEAD` present at commit time — a conflicted merge an operator
+# resolves and finishes with `git commit`. That commit records a deferral
+# instead of being refused; the immediately following commit must discharge
+# it, and `.githooks/pre-push` refuses the push if none ever does (#8047).
+#
+# The sanctioned landing sequence (`scripts/pm/os-regen-merge.sh`) does NOT
+# hit that exemption: its step 1 merge auto-commits with no hook run at all
+# (see below), so the marker is untouched going into step 3, whose commit is
+# an ORDINARY one this hook refuses on purpose — that refusal is the designed
+# collection point, "what main brought" read apart from "what the change
+# produces" by the fallback it prints, not a deferral.
 #
 # ⚠️ git does not run this hook for a merge it completes ITSELF — only for one
 # you finish with `git commit`. A clean auto-committed merge therefore lands

scripts/check-regen-pending.mjs

@@ -411,9 +411,11 @@ function main({ prePush = false } = {}) {
     console.error(
       `\nRegenerate ${owed}, \`git add\` them, and ${prePush ? 'commit the result before pushing' : 'commit again'}.\n`
         + '  This check clears itself the moment they are current — nothing to reset by hand.\n'
-        + '  Landing a merge? `bash scripts/pm/os-regen-merge.sh` runs the sanctioned sequence — it commits\n'
-        + '  the merge first (this hook records that as a deferral) and regeneration follows as its own\n'
-        + '  commit. Every artifact above also has a required gate on the PR.\n',
+        + '  Landing a merge? `bash scripts/pm/os-regen-merge.sh` runs the sanctioned sequence — its merge\n'
+        + '  auto-commits first with no hook run at all (git skips pre-commit for a merge it completes\n'
+        + '  itself), so THIS refusal, on the ordinary commit right after, is that sequence\'s designed\n'
+        + '  collection point — not a deferral. Regeneration follows as its own commit; every artifact\n'
+        + '  above also has a required gate on the PR.\n',
     );
     return 1;
   }