Fix feed filtering by feed_id and add dynamic feed navigation links

- Add feed_id to get_feed_events_for_user function output
- Add for_feed_id filter to feed_event entity type
- Update PvFeedEventList to filter events by selected feed
- Create PvManageFeedLink component for dynamic feed navigation
- Update PvFeedSelector to read feedId from query params
- Update Feed and Feed Management pages with new link component

Closes #134

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>