When a crew or other agent dispatches work to a polecat using `gt sling`,
the polecat now tracks who dispatched the work and sends them a completion
notification when running `gt done`.
Changes:
- Add DispatchedBy field to AttachmentFields in beads/fields.go
- Store dispatcher agent ID in bead when slinging (both direct and formula)
- Check for dispatcher in done.go and send WORK_DONE notification to them
This fixes the orchestration issue where crews were left waiting because
polecats only notified the Witness on completion, not the dispatcher.
Fixes: id-c17
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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
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