Optimizes `handleAuthLogin` in `js/app.js` to run user data fetching (blocks, subscriptions, hashtag preferences) in the background instead of blocking the main UI render. This significantly improves perceived login speed, especially for users with large lists or slow NIP-07 extensions.
- Moves `userBlocks.seedWithNpubs` (which involves publishing) to background.
- Moves `subscriptions.ensureLoaded` and `hashtagPreferences.load` (which involve decryption) to background.
- Adds a race condition for `userBlocks.ensureLoaded` (read-only) with a short timeout to attempt early hydration without blocking indefinitely.
- Ensures the UI updates reactively when background data arrives via existing event listeners.
Co-authored-by: PR0M3TH3AN <[email protected]>
