feat(sdk): Multi-Projekt-Architektur — mehrere Projekte pro Tenant

Jeder Tenant kann jetzt mehrere Compliance-Projekte anlegen (z.B. verschiedene
Produkte, Tochterunternehmen). CompanyProfile ist pro Projekt kopierbar und
danach unabhaengig editierbar. Multi-Tab-Support via separater BroadcastChannel
und localStorage Keys pro Projekt.

- Migration 039: compliance_projects Tabelle, sdk_states.project_id
- Backend: FastAPI CRUD-Routes fuer Projekte mit Tenant-Isolation
- Frontend: ProjectSelector UI, SDKProvider mit projectId, URL ?project=
- State API: UPSERT auf (tenant_id, project_id) mit Abwaertskompatibilitaet
- Tests: pytest fuer Model-Validierung, Row-Konvertierung, Tenant-Isolation
- Docs: MKDocs Seite, CLAUDE.md, Backend README

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

admin-compliance/app/sdk/page.tsx

@@ -4,6 +4,7 @@ import React from 'react'
 import Link from 'next/link'
 import { useSDK, SDK_PACKAGES, getStepsForPackage } from '@/lib/sdk'
 import { CustomerTypeSelector } from '@/components/sdk/CustomerTypeSelector'
+import { ProjectSelector } from '@/components/sdk/ProjectSelector/ProjectSelector'
 import type { CustomerType, SDKPackageId } from '@/lib/sdk/types'
 
 // =============================================================================
@@ -42,15 +43,18 @@ function PackageCard({
   completion,
   stepsCount,
   isLocked,
+  projectId,
 }: {
   pkg: (typeof SDK_PACKAGES)[number]
   completion: number
   stepsCount: number
   isLocked: boolean
+  projectId?: string
 }) {
   const steps = getStepsForPackage(pkg.id)
   const firstStep = steps[0]
-  const href = firstStep?.url || '/sdk'
+  const baseHref = firstStep?.url || '/sdk'
+  const href = projectId ? `${baseHref}?project=${projectId}` : baseHref
 
   const content = (
     <div
@@ -133,16 +137,19 @@ function QuickActionCard({
   icon,
   href,
   color,
+  projectId,
 }: {
   title: string
   description: string
   icon: React.ReactNode
   href: string
   color: string
+  projectId?: string
 }) {
+  const finalHref = projectId ? `${href}?project=${projectId}` : href
   return (
     <Link
-      href={href}
+      href={finalHref}
       className="flex items-center gap-4 p-4 bg-white rounded-xl border border-gray-200 hover:border-purple-300 hover:shadow-md transition-all"
     >
       <div className={`p-3 rounded-lg ${color}`}>{icon}</div>
@@ -162,7 +169,12 @@ function QuickActionCard({
 // =============================================================================
 
 export default function SDKDashboard() {
-  const { state, packageCompletion, completionPercentage, setCustomerType } = useSDK()
+  const { state, packageCompletion, completionPercentage, setCustomerType, projectId } = useSDK()
+
+  // No project selected → show project list
+  if (!projectId) {
+    return <ProjectSelector />
+  }
 
   // Calculate total steps
   const totalSteps = SDK_PACKAGES.reduce((sum, pkg) => {
@@ -282,7 +294,7 @@ export default function SDKDashboard() {
                 Laden Sie Ihre vorhandenen Compliance-Dokumente hoch. Unsere KI analysiert sie und zeigt Ihnen, welche Erweiterungen fuer KI-Compliance erforderlich sind.
               </p>
               <Link
-                href="/sdk/import"
+                href={projectId ? `/sdk/import?project=${projectId}` : '/sdk/import'}
                 className="inline-flex items-center gap-2 mt-4 px-4 py-2 bg-indigo-600 text-white rounded-lg hover:bg-indigo-700 transition-colors"
               >
                 <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
@@ -345,6 +357,7 @@ export default function SDKDashboard() {
                 completion={packageCompletion[pkg.id]}
                 stepsCount={visibleSteps.length}
                 isLocked={isPackageLocked(pkg.id)}
+                projectId={projectId}
               />
             )
           })}
@@ -365,6 +378,7 @@ export default function SDKDashboard() {
             }
             href="/sdk/advisory-board"
             color="bg-purple-50"
+            projectId={projectId}
           />
           <QuickActionCard
             title="Security Screening"
@@ -376,6 +390,7 @@ export default function SDKDashboard() {
             }
             href="/sdk/screening"
             color="bg-red-50"
+            projectId={projectId}
           />
           <QuickActionCard
             title="DSFA generieren"
@@ -387,6 +402,7 @@ export default function SDKDashboard() {
             }
             href="/sdk/dsfa"
             color="bg-blue-50"
+            projectId={projectId}
           />
           <QuickActionCard
             title="Legal RAG"
@@ -398,6 +414,7 @@ export default function SDKDashboard() {
             }
             href="/sdk/rag"
             color="bg-green-50"
+            projectId={projectId}
           />
         </div>
       </div>