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/sidebar.tsx

@@ -73,6 +73,9 @@ const getNavSections = (role: string): NavSection[] => {
                 { label: 'Call Recordings', href: '/call-recordings', icon: IconFileAudio },
                 { label: 'Missed Calls', href: '/missed-calls', icon: IconPhoneMissed },
             ]},
+            { label: 'Marketing', items: [
+                { label: 'Campaigns', href: '/campaigns', icon: IconBullhorn },
+            ]},
             { label: 'Admin', items: [
                 { label: 'Settings', href: '/settings', icon: IconGear },
             ]},