修复异机备份凭证与中断恢复（07-27-offhost-backup-final-fixes）

scripts/run-automatic-backup.sh

@@ -341,12 +341,15 @@ print(f"{unquote(value.username)}\t{database_name}")
   [[ "$source_image_digest" =~ ^sha256:[0-9a-f]{64}$ ]] || fail "active server image digest is invalid"
 
   CURRENT_PHASE="paired_backup"
-  if ! capture_command paired_backup env \
-    DATABASE_URL="$database_url" DB_TOOL_MODE=docker DB_CONTAINER="$DB_CONTAINER" \
-    POSTGRES_DB="$postgres_db" POSTGRES_USER="$postgres_user" POSTGRES_PASSWORD="$postgres_password" \
-    STORAGE_DIR_HOST="$STORAGE_HOST_DIR" BACKUP_DIR="$AUTOMATIC_BACKUP_DIR" \
-    BACKUP_RUN_ID="$run_id" BUILD_SHA="$BUILD_SHA" SOURCE_IMAGE_DIGEST="$source_image_digest" \
-    "$ROOT_DIR/scripts/backup-all.sh"; then
+  if ! (
+    export DATABASE_URL="$database_url"
+    export DB_TOOL_MODE=docker DB_CONTAINER
+    export POSTGRES_DB="$postgres_db" POSTGRES_USER="$postgres_user"
+    export POSTGRES_PASSWORD="$postgres_password"
+    export STORAGE_DIR_HOST="$STORAGE_HOST_DIR" BACKUP_DIR="$AUTOMATIC_BACKUP_DIR"
+    export BACKUP_RUN_ID="$run_id" BUILD_SHA SOURCE_IMAGE_DIGEST="$source_image_digest"
+    capture_command paired_backup "$ROOT_DIR/scripts/backup-all.sh"
+  ); then
     fail "paired backup command failed"
   fi
   [[ -d "$batch_dir" && -f "$batch_dir/manifest.json" ]] || fail "complete local batch was not published"