feat: appointments page, data refresh on login, multi-agent spec + plan

- Appointment Master page with status tabs, search, PhoneActionCell
- Login calls DataProvider.refresh() to load data after auth
- Sidebar: appointments nav for CC agents + executives
- Multi-agent SIP + lockout spec and implementation plan

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

src/main.tsx

@@ -21,6 +21,7 @@ import { IntegrationsPage } from "@/pages/integrations";
 import { AgentDetailPage } from "@/pages/agent-detail";
 import { SettingsPage } from "@/pages/settings";
 import { MyPerformancePage } from "@/pages/my-performance";
+import { AppointmentsPage } from "@/pages/appointments";
 import { AuthProvider } from "@/providers/auth-provider";
 import { DataProvider } from "@/providers/data-provider";
 import { RouteProvider } from "@/providers/router-provider";
@@ -55,6 +56,7 @@ createRoot(document.getElementById("root")!).render(
                                 <Route path="/my-performance" element={<MyPerformancePage />} />
                                 <Route path="/call-desk" element={<CallDeskPage />} />
                                 <Route path="/patients" element={<PatientsPage />} />
+                                <Route path="/appointments" element={<AppointmentsPage />} />
                                 <Route path="/team-dashboard" element={<TeamDashboardPage />} />
                                 <Route path="/reports" element={<ReportsPage />} />
                                 <Route path="/integrations" element={<IntegrationsPage />} />