[ psic4t/nospeak ] feat: add PWA connection keep-alive and visibility recovery
Add application-level ping mechanism and visibility change handling to
prevent relay connections from silently dropping in PWA/browser when
backgrounded for extended periods (e.g., NAT timeout after ~5 minutes).
Changes:
- Add 120-second ping interval using lightweight Nostr subscription
- Add 5-second ping timeout to detect dead connections
- Add visibility change listener to verify connections when tab resumes
[ papiche/Astroport.ONE ] Remove the cleanup_processed_videos function from youtube.com.sh to streamline the synchronization process. This change eliminates unnecessary cleanup of processed video entries, focusing on verifying videos marked without event IDs instead. The update enhances code clarity and maintains functionality for managing processed videos.