[FEATURE] Remove video from feed when blocking a channel or marking as watched

Problem Statement

When the video or channel marked as watched or marked as blocked, it still appears in the feed which is confusing.

Proposed Solution

Remove the video from the feed (might show (but not really critical imo) a banner that it was removed, in the same place as the video was.

Priority Assessment

• [ ] Critical — I can't use Flow effectively without this
• [ ] High — I'd use this feature daily
• [ ] Medium — Nice to have, would improve my experience noticeably
• [x] Low — Minor improvement, not urgent

Feature Category

• [ ] Video playback
• [ ] Music player
• [x] Home feed / Recommendations
• [ ] Search & Discovery
• [ ] Downloads & Offline
• [ ] Subscriptions & Channels
• [ ] Playlists & Queue
• [ ] Picture-in-Picture / Background playback
• [ ] Notifications & Alerts
• [ ] Settings & Customization
• [ ] Import / Export / Migration
• [ ] Casting & External devices
• [ ] SponsorBlock / DeArrow
• [ ] Lyrics / Subtitles
• [ ] UI / Theming / Accessibility
• [ ] Performance / Battery / Data usage
• [ ] Privacy & Security
• [ ] Other