fix(api): resolve image server hardcoding and add comprehensive diagnostics

- Fix fetchImageRateLimits to accept configurable imageServer parameter instead
  of hardcoded DEFAULT_IMAGE_API_SERVER
- Add enhanced diagnostic logging for image server operations with server
  context, error tracking, and user registration status
- Update AccountViewView.vue to pass correct image server parameter
- Ensure consistent server switching behavior across all API endpoints
- Prevent similar server configuration issues in image operations

Fixes server switching not applying to image rate limit checks and provides
complete visibility into image server operations for debugging and monitoring.

src/views/AccountViewView.vue

@@ -1440,7 +1440,11 @@ export default class AccountViewView extends Vue {
         webPushServer: this.webPushServer,
       });
 
-      const imageResp = await fetchImageRateLimits(this.axios, did);
+      const imageResp = await fetchImageRateLimits(
+        this.axios,
+        did,
+        this.DEFAULT_IMAGE_API_SERVER,
+      );
 
       if (imageResp.status === 200) {
         this.imageLimits = imageResp.data;