Make CVE ID and Vendor optional when creating Jira tickets. Add source_context
field to track ticket origin (cve, archer, ivanti_queue, email, manual).
- Migration: drop NOT NULL on cve_id/vendor, add source_context column with CHECK
- Backend: update create/update/get endpoints for optional fields and source_context
- Frontend: update creation modal with optional labels and source context dropdown
- Add Create Jira Ticket action from Ivanti queue (pre-populates from finding)
- Add Create Jira Ticket action from Archer detail view (pre-populates from ticket)
- Add source context badge column, filter dropdown, and search to ticket list
