[P2] Comments and activity feed

[KalebCole]

Priority: P2 (Medium) Post comments and view activity feed on events. ## Use Cases - Post updates to event discussion - See who commented or liked - Engage with guests before event ## Proposed Commands bash # View activity feed partiful activity <eventId> partiful activity <eventId> --limit 20 # Post a comment partiful comment <eventId> "Excited for tomorrow!" # Reply to a comment partiful comment <eventId> --reply <commentId> "Me too!" ## Output Activity Feed: Game Night ========================= [2h ago] John Doe RSVP Going [3h ago] Jane Smith commented: "Should I bring snacks?" └─ You replied: "Yes please!" [1d ago] Bob Wilson RSVP Maybe [2d ago] Event created ## Acceptance Criteria - [ ] View activity feed - [ ] Post comments - [ ] Reply to comments - [ ] See RSVP activity in feed