feat: add reporting frontend, fix module categorization, update docs

- Create Reporting module frontend (page.tsx) with executive dashboard
  showing compliance score, risk overview, deadlines, module KPIs
- Create Reporting lib (types.ts, api.ts) matching Go backend models
- Add Reporting to STEP_EXPLANATIONS and both SDK sidebars
- Remove DSB Portal, Multi-Tenant, SSO from SDK sidebars (admin-only)
- Add Multi-Tenant, SSO, DSB Portal to dashboard navigation.ts
  with 'Plattform-Verwaltung' subgroup
- Update docs: academy.md (PDF certs), reporting.md (new),
  index.md (SDK vs Admin categorization), mkdocs.yml (all modules)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

admin-compliance/components/sdk/SDKPipelineSidebar/SDKPipelineSidebar.tsx

@@ -311,10 +311,8 @@ function SidebarContent({ onNavigate }: SidebarContentProps) {
             { href: '/sdk/academy', label: 'Academy', icon: '🎓' },
             { href: '/sdk/whistleblower', label: 'Whistleblower', icon: '📢' },
             { href: '/sdk/incidents', label: 'Incidents', icon: '🚨' },
-            { href: '/sdk/dsb-portal', label: 'DSB Portal', icon: '👤' },
+            { href: '/sdk/reporting', label: 'Reporting', icon: '📈' },
             { href: '/sdk/industry-templates', label: 'Branchenvorlagen', icon: '🏢' },
-            { href: '/sdk/multi-tenant', label: 'Multi-Tenant', icon: '👥' },
-            { href: '/sdk/sso', label: 'SSO', icon: '🔑' },
             { href: '/sdk/document-crawler', label: 'Doc Crawler', icon: '📄' },
             { href: '/sdk/advisory-board', label: 'Beirat', icon: '💬' },
           ].map(mod => (