Propagate draft format through live scoring

## Problem

`LiveSession` and its ratings-loader callbacks receive only a set code, while scoring progress assumes 14 picks per pack and 42 cards. The 17Lands layer supports event-format inputs, but the detected live format never reaches it. Pick-Two also separates logical-pick progress from cards selected.

## Proposed change

Carry the detected format/rules through CLI/TUI session construction, live snapshots, rating selection, scoring context, pending recovery, and accountless state. Define an explicit ratings-source mapping per supported draft format and keep progress arithmetic rule-driven.

## Acceptance Criteria

- [ ] Live snapshots expose the detected draft format and format rules.
- [ ] Rating loaders receive an explicit format/source mapping instead of assuming Quick Draft.
- [ ] Quick and Premier use the intended 17Lands format; Traditional and Pick-Two have explicit, tested fallback behavior when no exact feed exists.
- [ ] Pack/pick progress is derived from format rules, not global 14/42 constants.
- [ ] A multi-card pick is consumed atomically in account-backed and transient sessions.
- [ ] Pending recovery restores the correct format, pack, pick, and selected-card state.
- [ ] Focused live-session/scoring tests and the changelog cover every format.

## Scope notes

No pair-combination scoring algorithm and no frontend layout changes.