fix(jira): show test Jira tickets on technique page (correct entity model)

Techniques don't have their own Jira tickets — tickets exist on tests
and campaigns. The previous JiraLinkPanel entityType='technique' always
returned empty.

Backend: add entity_ids (list) filter to GET /jira/links so multiple
  test IDs can be fetched in a single request.
Frontend API: listJiraLinks() accepts entity_ids[] and serialises them
  as repeated query params (required by FastAPI List[UUID] parsing).
TechniqueDetailPage: replace JiraLinkPanel with TechniqueJiraSection —
  a dedicated read-only component that:
  - Takes technique.tests (already loaded)
  - Batch-fetches all test Jira links in one request
  - Shows test name + ticket key + status + priority + open-in-Jira link
  - Hides itself when no tickets exist (avoids empty panel)

frontend/src/api/jira.ts

@@ -60,7 +60,17 @@ export async function createJiraLink(
 export async function listJiraLinks(params?: {
   entity_type?: JiraLinkEntityType;
   entity_id?: string;
+  /** Batch-fetch links for multiple entity IDs (passed as repeated query params). */
+  entity_ids?: string[];
 }): Promise<JiraLink[]> {
+  // Axios doesn't repeat array params by default — build URLSearchParams manually
+  if (params?.entity_ids && params.entity_ids.length > 0) {
+    const p = new URLSearchParams();
+    if (params.entity_type) p.append("entity_type", params.entity_type);
+    for (const id of params.entity_ids) p.append("entity_ids", id);
+    const { data } = await client.get<JiraLink[]>(`/jira/links?${p.toString()}`);
+    return data;
+  }
   const { data } = await client.get<JiraLink[]>("/jira/links", { params });
   return data;
 }