Add multi-item Jira ticket creation from Ivanti Queue

Select multiple queue items and create a single consolidated Jira ticket
with aggregated summary and description. Adds multi-select mode with
checkboxes, floating action bar, consolidation modal, and junction table
to track which queue items contributed to each ticket.

- Migration: jira_ticket_queue_items junction table
- POST /api/jira-tickets/:id/queue-items endpoint
- GET /api/ivanti/todo-queue/ticket-links endpoint
- ConsolidationModal component with aggregation logic
- IvantiTodoQueuePage with selection mode and ticket link badges
- Pure utility functions for summary/description generation
- 34 tests passing (backend + frontend)

backend/routes/ivantiTodoQueue.js

@@ -396,6 +396,41 @@ function createIvantiTodoQueueRouter() {
         }
     });
 
+    /**
+     * GET /api/ivanti/todo-queue/ticket-links
+     *
+     * Returns Jira ticket associations for the current user's queue items.
+     * Joins jira_ticket_queue_items with jira_tickets to get ticket_key and url.
+     *
+     * @returns {Object} { links: { [queue_item_id]: { ticket_key, jira_url } } }
+     * @error 500 Internal server error
+     */
+    router.get('/ticket-links', requireAuth(), async (req, res) => {
+        try {
+            const { rows } = await pool.query(
+                `SELECT jtqi.queue_item_id, jt.ticket_key, jt.url AS jira_url
+                 FROM jira_ticket_queue_items jtqi
+                 JOIN jira_tickets jt ON jt.id = jtqi.jira_ticket_id
+                 JOIN ivanti_todo_queue q ON q.id = jtqi.queue_item_id
+                 WHERE q.user_id = $1`,
+                [req.user.id]
+            );
+
+            const links = {};
+            for (const row of rows) {
+                links[row.queue_item_id] = {
+                    ticket_key: row.ticket_key,
+                    jira_url: row.jira_url
+                };
+            }
+
+            res.json({ links });
+        } catch (err) {
+            console.error('Error fetching ticket links:', err);
+            res.status(500).json({ error: 'Internal server error.' });
+        }
+    });
+
     /**
      * DELETE /api/ivanti/todo-queue/completed
      *