fix(agents-tools): never block commits on missing bumper; robust .version parse

scripts/agents-tools/test-version-bump.sh

@@ -87,6 +87,34 @@ git log -1 --pretty=%s | grep -qF 'add specs (v1.1.0)' || fail "e2e structure me
 echo z > specs/z.md
 git add -A; git commit -q -m "edit spec"
 [ "$(cat .version)" = 1.1.1 ] || fail "e2e content: want 1.1.1 got $(cat .version)"
+git log -1 --pretty=%s | grep -qF 'edit spec (v1.1.1)' || fail "e2e content message: $(git log -1 --pretty=%s)"
 
 cd /; rm -rf "$r"
 echo "e2e OK"
+
+# ── corrupt .version recovers to a clean baseline ────────────────────────────
+r="$(new_repo)"; cd "$r"
+mkdir -p plans; : > plans/.gitkeep
+echo 1.0.0 > .version
+git add -A; "$SCRIPT" precommit; git commit -q -m init
+printf '1.\n' > .version          # partial/corrupt
+echo hi > plans/a.md
+git add -A; "$SCRIPT" precommit
+[ "$(cat .version)" = 1.0.1 ] || fail "corrupt recovery: want 1.0.1 got $(cat .version)"
+cd /; rm -rf "$r"
+echo "corrupt-recovery OK"
+
+# ── hook never blocks a commit when version-bump is missing ──────────────────
+r="$(new_repo)"; cd "$r"
+mkdir -p .agents-tools/hooks
+cp "$HERE/hooks/pre-commit" .agents-tools/hooks/pre-commit
+cp "$HERE/hooks/prepare-commit-msg" .agents-tools/hooks/prepare-commit-msg
+chmod +x .agents-tools/hooks/pre-commit .agents-tools/hooks/prepare-commit-msg
+# note: .agents-tools/version-bump intentionally NOT copied
+git config core.hooksPath .agents-tools/hooks
+echo hi > file.txt
+git add -A
+git commit -q -m "no bumper present" || fail "missing version-bump blocked the commit"
+git rev-parse -q --verify HEAD >/dev/null || fail "commit did not happen"
+cd /; rm -rf "$r"
+echo "hook-resilience OK"