revert(infra): restore first-deploy-only workflow import

Workflows now persist in n8n volume with credential links intact.
Only import on first deploy, skip if already exists.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: ImTotem

infra/scripts/init_n8n.sh

@@ -80,11 +80,8 @@ fi
 echo "3. Setting up owner account..."
 setup_owner
 
-echo "4. Importing workflows..."
-# Force reimport to apply JSON changes (credential links via predefinedCredentialType)
-$COMPOSE exec -T n8n n8n import:workflow --input="/workflows/pg_sheets_sync.json" 2>&1
-$COMPOSE exec -T n8n n8n import:workflow --input="/workflows/link_auto_expire.json" 2>&1
-$COMPOSE exec -T n8n n8n publish:workflow --id="pg-sheets-sync" 2>&1 || true
-$COMPOSE exec -T n8n n8n publish:workflow --id="link-auto-expire" 2>&1 || true
+echo "4. Importing workflows (first deploy only)..."
+import_if_new "/workflows/pg_sheets_sync.json" "pg-sheets-sync"
+import_if_new "/workflows/link_auto_expire.json" "link-auto-expire"
 
 echo "=== n8n Init complete ==="