Prioritize user lists syncing during login

Prioritize fetching of block lists, subscriptions, and other user data before loading the main video feed during login.
- In `handleAuthLogin`, stop the existing video feed subscription immediately to free up bandwidth.
- Explicitly await `subscriptions.ensureLoaded(activePubkey)` alongside `userBlocks.seedWithNpubs` before triggering `refreshAllVideoGrids`.
This ensures user context is fully loaded before the heavy feed sync starts, addressing slow sync issues especially with NIP-07.

Co-authored-by: PR0M3TH3AN <[email protected]>

js/app.js

@@ -4097,6 +4097,15 @@ class Application {
       this.resetViewLoggingState();
     }
 
+    // Stop existing feed subscription to prioritize user data sync
+    if (
+      this.videoSubscription &&
+      typeof this.videoSubscription.unsub === "function"
+    ) {
+      this.videoSubscription.unsub();
+      this.videoSubscription = null;
+    }
+
     this.applyAuthenticatedUiState();
     this.commentController?.refreshAuthState?.();
     this.updateShareNostrAuthState({ reason: "auth-login" });
@@ -4279,6 +4288,15 @@ class Application {
           );
         }
       }
+
+      try {
+        await subscriptions.ensureLoaded(activePubkey);
+      } catch (error) {
+        devLogger.warn(
+          "[Application] Failed to load subscriptions during login:",
+          error,
+        );
+      }
     }
 
     try {