feat: mid-session status updates — ticket notes, client updates, email drafts

Engineers can now generate AI-powered status updates during active FlowPilot
sessions and after resolve/escalate. Three audiences (Ticket Notes, Client
Update, Email Draft) with Quick/Detailed length options. Copy to clipboard
with one click. Client names auto-inserted from intake/PSA context.

Backend: new endpoint POST /ai-sessions/{id}/status-update with audience-aware
system prompts. Frontend: StatusUpdateModal with 2-step selection flow,
Share Update button in action bar, Share Resolution/Escalation on completed
sessions. Also updates Solutions Library spec with Community tier design.

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

frontend/src/pages/FlowPilotSessionPage.tsx

@@ -237,6 +237,7 @@ export default function FlowPilotSessionPage() {
           }}
           onRate={fp.rateSession}
           onReloadSession={() => fp.loadSession(fp.session!.id)}
+          onGenerateStatusUpdate={fp.generateStatusUpdate}
         />
       </div>
     </div>