feat: add cockpit frontend types and API methods (Phase 3)

- TriageMeta, EvidenceItem, TriageUpdate interfaces
- QuestionItem.options field for quick-reply buttons
- triage_update on ChatMessageResponse
- Triage fields on AISessionDetail for session resume
- updateTriage() and getHandoffDraft() API methods

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/api/aiSessions.ts

@@ -18,6 +18,7 @@ import type {
   ChatSessionCreateResponse,
   ChatMessageRequest,
   ChatMessageResponse,
+  TriageMeta,
 } from '@/types/ai-session'
 
 export const aiSessionsApi = {
@@ -241,6 +242,26 @@ export const aiSessionsApi = {
     )
     return response.data
   },
+
+  async updateTriage(sessionId: string, fields: Partial<TriageMeta>): Promise<TriageMeta> {
+    const response = await apiClient.patch<TriageMeta>(
+      `/ai-sessions/${sessionId}/triage`,
+      fields
+    )
+    return response.data
+  },
+
+  async getHandoffDraft(sessionId: string): Promise<string> {
+    const response = await apiClient.post<string>(
+      `/ai-sessions/${sessionId}/handoff-draft`,
+      {},
+      { headers: { Accept: 'text/event-stream' }, responseType: 'text' }
+    )
+    // Response is SSE format: "data: {...}\n\n"
+    const raw = typeof response.data === 'string' ? response.data : ''
+    const dataLine = raw.split('\n').find(l => l.startsWith('data: '))
+    return dataLine ? dataLine.slice(6) : raw
+  },
 }
 
 export default aiSessionsApi