* feat(portal-api): add Cognito shift API for the employee portal (DEV-287)
Employees and admins can pick, drop, swap, and manage coverage through
GET/POST/DELETE /api/shifts. Roster PUT accepts optional email for portal
identity. Slack slash commands and App Home admin modals stay in place.
Co-authored-by: adam <adam@seahavenind.com>
* fix(portal-api): preserve shift and deployment invariants (DEV-287)
Co-authored-by: adam <adam@seahavenind.com>
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Co-authored-by: Cursor Agent <cursoragent@cursor.com>
