Import Zoom meeting attendance and Phone call history

The situation

Zoom meeting rosters and Zoom Phone history contain evidence of actual calls. Calendar conference links establish scheduled events, but cannot establish attendance or talk time.

What works today, and why it is not enough

The call-history CLI in #1406 accepts normalized evidence and lists calls and per-person counts. A Zoom user still needs to retrieve native history and map it into that contract manually. It has no Zoom adapter.

Ask

Add bounded imports for complete supplied rosters, accessible past-meeting attendance and the owner's Zoom Phone history through the daemon call API.

Merge order:

1. #1406: call observations and summaries.
2. Zoom calls 1/4: import complete supplied meeting rosters and reconcile corrected attendance.
3. Zoom calls 2/4: fetch attendance for an exact past-meeting UUID.
4. Zoom calls 3/4: discover the selected owner's hosted past meetings.
5. Zoom calls 4/4: import the owner's Zoom Phone call elements.

Each numbered PR adds one commit on its immediate predecessor. All target main; review each PR's own commit or predecessor comparison until the earlier PRs merge. Rebase the remaining series onto main as dependencies merge.

Use explicit account/owner identities and archive bindings. Names, invitations, waiting-room time and elapsed duration cannot establish attendance or talk time. Keep protected desktop databases, account-wide Phone access, background scheduling and automatic OAuth enrollment outside this series. Users manage their own OAuth apps and token helpers; no new Go dependency is needed.