Show raw Jira status everywhere instead of mapping to Open/In Progress/Closed

- Drop CHECK constraint on jira_tickets.status to allow any status string
- Store raw Jira status directly in status column during sync (remove mapJiraStatusToLocal)
- Remove VALID_TICKET_STATUSES validation on create/update endpoints
- Remove separate Jira Status column from table (status IS the Jira status now)
- Update frontend status badges to color-code dynamically based on status category
- Update Open Tickets widget and CVE detail view to use isClosedStatus() helper
- Make filter dropdown dynamic based on actual ticket statuses
- Add migration script for dropping the constraint on other deployments

backend/db-schema.sql

@@ -126,7 +126,7 @@ CREATE TABLE IF NOT EXISTS jira_tickets (
     ticket_key TEXT NOT NULL,
     url TEXT,
     summary TEXT,
-    status TEXT DEFAULT 'Open' CHECK (status IN ('Open', 'In Progress', 'Closed')),
+    status TEXT DEFAULT 'Open',
     created_at TIMESTAMPTZ DEFAULT NOW(),
     updated_at TIMESTAMPTZ DEFAULT NOW()
 );