feat: wizard step indicator, wider dialog, campaigns in admin sidebar, clear leads shortcut

- Import wizard: added step indicator (numbered circles), widened to max-w-5xl
- Admin sidebar: added Marketing → Campaigns nav link
- Clear campaign leads: Ctrl+Shift+C shortcut with campaign picker modal (test-only)
- Test CSV data for all 3 campaigns
- Defect fixing plan + CSV import spec docs
- Session memory update

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

src/components/layout/app-shell.tsx

@@ -7,6 +7,7 @@ import { SipProvider } from '@/providers/sip-provider';
 import { useSip } from '@/providers/sip-provider';
 import { CallWidget } from '@/components/call-desk/call-widget';
 import { MaintOtpModal } from '@/components/modals/maint-otp-modal';
+import { ClearCampaignLeadsModal } from '@/components/modals/clear-campaign-leads-modal';
 import { AgentStatusToggle } from '@/components/call-desk/agent-status-toggle';
 import { NotificationBell } from './notification-bell';
 import { useAuth } from '@/providers/auth-provider';
@@ -79,7 +80,8 @@ export const AppShell = ({ children }: AppShellProps) => {
                 </div>
                 {isCCAgent && pathname !== '/' && pathname !== '/call-desk' && <CallWidget />}
             </div>
-            <MaintOtpModal isOpen={isOpen} onOpenChange={(open) => !open && close()} action={activeAction} />
+            <MaintOtpModal isOpen={isOpen && activeAction?.endpoint !== '__client__clear-campaign-leads'} onOpenChange={(open) => !open && close()} action={activeAction} />
+            <ClearCampaignLeadsModal isOpen={isOpen && activeAction?.endpoint === '__client__clear-campaign-leads'} onOpenChange={(open) => !open && close()} />
         </SipProvider>
     );
 };