[ChristopherPHolder]

What and why

Closes #127.

CONTEXT.md defines office time, the office day and office hours, but the zone was in Reminder, and office hours, the office day and the clock were in Banter. The Responder imported Banter for office hours, and the summary imported it for the clock. OfficeTime now owns them:

• OFFICE_TIME_ZONE and inOfficeTime;
• isOfficeHours, renamed from isBanterTime to the word CONTEXT.md uses, with OFFICE_HOURS replacing BANTER_HOURS;
• startOfOfficeDay, startOfOfficeWeek and officeClock.

Banter, Reminder, the Responder and the summary use it. Banter keeps the banter periods, its log and its schedule. Nothing behaves differently.

This comes first in the folder split (#128 to #131), so answering and recording won't depend on announcing just to tell the time.

How I tested it

• The office-hours tests moved to OfficeTime.test.ts. I added tests for the office day and week starting at midnight office time, Monday as the start of the week, and the clock.
• pnpm vp run ci passes.

Checklist

• vp run ci passes
• Tests cover the change
• Docs updated if what gets posted, the configuration, the Console or the deploy changed (module table only)
• New environment variables are wired through (none)
• Ready to ship: merging this deploys it to production