Add Twitter-style thread visualization for parent and reply posts #142
Description
Description
Add a Twitter/X-style ancestor line for parent posts and use a similar visual mechanic for children/reply posts. This makes thread structure immediately visible.
Acceptance Criteria
- Parent posts display a vertical ancestor line connecting them to the current post
- Reply/children posts use a similar visual connector
- Thread depth is visually clear
- The visualization works correctly for varying thread depths