Read-only UI — ticket list + detail view

[abdotop]

Depends on: Issue 8, Issue 9, Issue 11

A read-only list + detail view of a project's Ticket[], built against the
confirmed real data shape from Issue 11 (not a guessed one). Status badge
per source, deduced status, assignees/reviewers, discussion feed on the
detail view, links out to each source.

Acceptance criteria

• List view: one row per Ticket, deduced status, assignees
• Detail view: per-source status badges + full discussion feed
• No write actions anywhere in this view