Phase 3 — Does it run

The central question is **"does it run"** — quorum, not just a date on a calendar. This phase makes Orrey answer it: quorum auto-confirm, jeopardy notices, a reminder ladder with DM fallback, attendance auto-assume with correction, flake memory, a thread per session, and the `/upcoming` and `/whos-in` commands.

Everything time-triggered here posts a **new** notice. Nothing edits an existing message.

## In order
1. #27 — A thread per session
1. #28 — Quorum auto-confirm
1. #29 — Jeopardy notices at T-24h
1. #30 — Reminder ladder with DM fallback (error 50007)
1. #31 — Attendance auto-assume at session end + per-person correction toggles
1. #32 — Flake memory
1. #33 — /upcoming and /whos-in

Start by reading the linked work items #27–#33 in the stated order; this issue is a phase-level summary rather than a standalone implementation task. Done means the listed quorum, notice, reminder, attendance, flake-memory, thread, and command work is complete, with every time-triggered action posting a new notice rather than editing an existing message.

Escrito por el modelo de indexación a partir del texto del issue.