feat: two-phase resolve with streaming ticket notes generation

ConcludeSessionModal now resolves instantly (Phase 1) then streams
ticket notes via SSE (Phase 2), with skeleton loading and fallback.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/pages/AssistantChatPage.tsx

@@ -396,21 +396,19 @@ export default function AssistantChatPage() {
   const handleConclude = async (outcome: ConclusionOutcome, _notes: string): Promise<string> => {
     if (!activeChatId) throw new Error('No active chat')
 
-    // Map conclusion outcomes to ai_sessions actions
     if (outcome === 'resolved') {
-      const result = await aiSessionsApi.resolveSession(activeChatId, {
+      await aiSessionsApi.resolveSession(activeChatId, {
         resolution_summary: _notes || 'Resolved via assistant chat',
       })
-      return result.documentation?.problem_summary || 'Session resolved'
+      return activeChatId
     } else if (outcome === 'escalated') {
-      const result = await aiSessionsApi.escalateSession(activeChatId, {
+      await aiSessionsApi.escalateSession(activeChatId, {
         escalation_reason: _notes || 'Escalated from assistant chat',
       })
-      return result.documentation?.problem_summary || 'Session escalated'
+      return activeChatId
     } else {
-      // paused
       await aiSessionsApi.pauseSession(activeChatId)
-      return 'Session paused'
+      return activeChatId
     }
   }
 
@@ -830,6 +828,7 @@ export default function AssistantChatPage() {
         onConclude={handleConclude}
         onResumeNew={handleResumeNew}
         chatTitle={chats.find(c => c.id === activeChatId)?.title ?? 'Chat'}
+        sessionId={activeChatId}
       />
     </div>
     </>