chore: auto manifest on version bump; local manual script only

contrib/manifest/generate.py + pre-commit hook; install-git-hooks.sh creates
.local/build-release-manifest.sh (gitignored). Remove scripts/ from remote.

Makefile

@@ -6,7 +6,8 @@ DIST := ssh-monitor-$(VERSION).tar.gz
 dist: $(DIST)
 
 manifest:
-	./scripts/build-release-manifest.sh
+	@test -x .local/build-release-manifest.sh || (echo "Сначала: ./contrib/install-git-hooks.sh" >&2; exit 1)
+	./.local/build-release-manifest.sh
 
 $(DIST): ssh-monitor
 	git archive --format=tar.gz --prefix=ssh-monitor-$(VERSION)/ -o $(DIST) HEAD