The terminal's dashboard lists every fired flow alarm in one line each #6501

Part of #5930. The alarms in src/flow/alarm_*.ts are computed and shown nowhere in the terminal (#6346 covers home, /boards and MCP).

Done:

• [ ] The dashboard (src/tui/screens/dashboard.ts) draws, for an admin, one line per fired alarm with its says, above the rest; nothing when none fired.
• [ ] A non-admin reads public repositories alone.
• [ ] Test: a stuck approved pull draws the stuck line; a quiet database draws none.

Files: src/tui/screens/dashboard.ts, its test.

Before pushing: bun x tsc --noEmit and the dashboard tests.