feat: minimum notice per host

[Udit-takkar]

What does this PR do?

Screen.Recording.2026-01-16.at.7.50.14.PM.mov

Mandatory Tasks (DO NOT REMOVE)

• I have self-reviewed the code (A decent size PR without self-review might be rejected).
• I have updated the developer docs in /docs if this PR makes changes that would require a documentation change. If N/A, write N/A here and check the checkbox.
• I confirm automated tests are in place that prove my fix is effective or that my feature works.

How should this be tested?

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Summary by cubic

Adds per‑host minimum booking notice to event types. Hosts can override the event’s default notice; slot display and host routing now respect these settings.

• New Features

  • Set a custom minimum notice per host in the event type editor (new “Set minimum notice” dialog).
  • Store per-host notice on Host.minimumBookingNotice and persist via update handler and repo selects.
  • Slot generation uses the most permissive notice across hosts to show slots; at booking time, hosts are filtered out if their notice isn’t met.
  • Types, TRPC schemas, and UI components updated to carry minimumBookingNotice end-to-end.
  • Added i18n strings for the new UI.

• Migration

  • Adds minimumBookingNotice (integer, nullable) to Host. Run database migrations.

^{Written for commit a400f4c. Summary will update on new commits.}