Background job improvements

In Claude Code 2.1.117, the behavior of background job agents has changed.

• A System Prompt: Background job behavior has been added, guiding background jobs to describe progress and rewrite the final result into the message body.
• Jobs now explicitly display done / blocked / failed status so the classifier can extract results more accurately.
• The duplicate alias /runtime-verification for the Verify skill has been removed, while the default Verify skill remains.
• The /schedule command has changed its user-facing wording from triggers to routines.
• In addition to cron_expression, you can now schedule a one-time run using run_once_at (RFC3339 UTC).
• The management URL has also changed from claude.ai/code/scheduled to claude.ai/code/routines.
• ended_reason: "run_once_fired" means the one-time run has completed, and it can be set again with a new run_once_at.
• The timezone conversion guidance has also been expanded to cover one-time timestamps.