DC-010: Convert remaining bare res.json({success,...}) envelopes to response helper

Routes covered in this batch:
- routes/events.js (1 call: GET /status)
- routes/workflows.js (6 calls: GET/POST/PUT/DELETE /workflows, POST /test, POST /:id/toggle)
- routes/openclaw.js (4 calls: GET /:hostname, DELETE /:hostname, POST /connect, GET /status)
- routes/dns.js (1 call: POST /credentials per-server results envelope)

Wire format unchanged — each handler now produces the same {success, ...} shape via success(). Net result: every {success, ...} envelope in routes/ now flows through the response helper, leaving only the intentional raw-array calls (services.js) and error-path envelopes for separate cleanup.

dashcaddy-api/routes/dns.js

@@ -409,8 +409,7 @@ module.exports = function({
         }
       }
 
-      return res.json({
-        success: anySuccess,
+      return success(res, {
         message: anySuccess ? 'Credentials saved for one or more servers' : 'All server credential tests failed',
         results
       });