Safer sign-out checks, keyboard accessibility, and agent API paging

We widened the checks that keep unsent work from being lost, and cleared the spots that blocked keyboard-only use.

• Signing out now also checks for recordings still uploading — changes, attachments, and recordings are each counted and shown
• Switching accounts no longer leaves the previous account's sync state behind
• Permanently deleting from the trash now removes the original recording file too, and a recording that fails to upload is cleaned up right away instead of lingering on the server
• The mobile AI panel and the calendar/import confirmation dialogs now work with a keyboard — focus stays inside and Esc closes them
• Agent API: item listing is now paged (has_more and limit fields) — check has_more before treating a list as complete. Responses also carry an outcome field describing the result
• Document usage is calculated correctly after restoring a backup
• Connecting Google Calendar is now safer — the connection completes only in a window signed in to the account that started it. The connected-calendar list now shows a recent sync failure right away
• We amended the Terms of Service and Privacy Policy — how recordings and voice-file transcription are processed and when original audio is deleted, the retention periods of AI processors, responsibility for recordings that include other people’s voices, and guidance regarding children under 14
• (Android) The fix for the app closing along with a widget popup, and the accessibility of the canvas arrows, ship with the next app update
• Plus general stability improvements