feat: back up and restore the release-storage volume, not just Postgres

backup.sh now also streams the fiscal-hub container's release binaries
(dist tarball, never in Postgres) into BACKUP_DIR alongside the pg_dump,
with the same 14-backup retention; restore_releases.sh is the companion
restore. Verified with a real restore smoke test in production: the
restored dump's agent_releases row and the restored tarball's exe both
match the published sha256 exactly.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

deploy/hub/restore_releases.sh

@@ -0,0 +1,17 @@
+#!/usr/bin/env sh
+# Restore the release-storage volume (backup.sh's *.tgz) into the Hub.
+# DESTRUCTIVE for the current release binaries: asks for confirmation. The
+# AgentRelease metadata (version/sha256/status) lives in Postgres, not here —
+# restore that separately with restore.sh from a dump taken around the same time.
+#   ./restore_releases.sh ./backups/gti_fiscal_releases_20260923_224551.tgz
+set -eu
+[ $# -eq 1 ] || { echo "usage: $0 <releases_backup.tgz>" >&2; exit 2; }
+FILE="$(basename "$1")"
+COMPOSE="docker compose -f docker-compose.prod.yml --env-file .env"
+[ -s "${BACKUP_DIR:-./backups}/$FILE" ] || { echo "backup not found in ${BACKUP_DIR:-./backups}: $FILE" >&2; exit 1; }
+printf "This REPLACES the current release-storage contents with %s. Type RESTORE to continue: " "$FILE"
+read -r answer
+[ "$answer" = "RESTORE" ] || { echo "aborted"; exit 1; }
+$COMPOSE exec -T fiscal-hub sh -c 'rm -rf /app/data/releases && mkdir -p /app/data/releases'
+$COMPOSE exec -T fiscal-hub tar -C /app/data -xz < "${BACKUP_DIR:-./backups}/$FILE"
+echo "restore ok: $FILE"