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/layout.tsx

@@ -1,7 +1,7 @@
 'use client'
 
 import { useEffect, useState } from 'react'
-import { usePathname } from 'next/navigation'
+import { usePathname, useSearchParams } from 'next/navigation'
 import { SDKProvider } from '@/lib/sdk'
 import { SDKSidebar } from '@/components/sdk/Sidebar/SDKSidebar'
 import { CommandBar } from '@/components/sdk/CommandBar'
@@ -36,7 +36,7 @@ const SYNC_STATUS_CONFIG = {
 } as const
 
 function SDKHeader({ sidebarCollapsed }: { sidebarCollapsed: boolean }) {
-  const { state, currentStep, setCommandBarOpen, completionPercentage, syncState } = useSDK()
+  const { state, currentStep, setCommandBarOpen, completionPercentage, syncState, projectId } = useSDK()
 
   const syncConfig = SYNC_STATUS_CONFIG[syncState.status] || SYNC_STATUS_CONFIG.idle
 
@@ -47,6 +47,14 @@ function SDKHeader({ sidebarCollapsed }: { sidebarCollapsed: boolean }) {
         <div className="flex items-center gap-3">
           <nav className="flex items-center text-sm text-gray-500">
             <span>SDK</span>
+            {state.projectInfo && (
+              <>
+                <svg className="w-4 h-4 mx-2" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                  <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9 5l7 7-7 7" />
+                </svg>
+                <span className="text-gray-700 font-medium">{state.projectInfo.name}</span>
+              </>
+            )}
             <svg className="w-4 h-4 mx-2" fill="none" stroke="currentColor" viewBox="0 0 24 24">
               <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9 5l7 7-7 7" />
             </svg>
@@ -102,10 +110,19 @@ function SDKHeader({ sidebarCollapsed }: { sidebarCollapsed: boolean }) {
 
       {/* Session Info Bar */}
       <div className="flex items-center gap-4 px-6 py-1.5 bg-gray-50 border-t border-gray-100 text-xs text-gray-500">
-        {/* Projekt + Version */}
+        {/* Projekt-Name */}
         <span className="text-gray-700 font-medium">
-          {state.companyProfile?.companyName || 'Kein Projekt'}
+          {state.projectInfo?.name || state.companyProfile?.companyName || 'Kein Projekt'}
         </span>
+
+        {/* Firmenname (falls abweichend vom Projektnamen) */}
+        {state.projectInfo && state.companyProfile?.companyName && state.companyProfile.companyName !== state.projectInfo.name && (
+          <>
+            <span className="text-gray-300">|</span>
+            <span className="text-gray-600">{state.companyProfile.companyName}</span>
+          </>
+        )}
+
         <span className="font-mono text-gray-400">
           V{String(state.projectVersion || 1).padStart(3, '0')}
         </span>
@@ -149,7 +166,7 @@ function SDKHeader({ sidebarCollapsed }: { sidebarCollapsed: boolean }) {
 // =============================================================================
 
 function SDKInnerLayout({ children }: { children: React.ReactNode }) {
-  const { isCommandBarOpen, setCommandBarOpen } = useSDK()
+  const { isCommandBarOpen, setCommandBarOpen, projectId } = useSDK()
   const [sidebarCollapsed, setSidebarCollapsed] = useState(false)
   const pathname = usePathname()
 
@@ -172,16 +189,18 @@ function SDKInnerLayout({ children }: { children: React.ReactNode }) {
 
   return (
     <div className="min-h-screen bg-gray-50">
-      {/* Sidebar */}
-      <SDKSidebar
-        collapsed={sidebarCollapsed}
-        onCollapsedChange={handleCollapsedChange}
-      />
+      {/* Sidebar — only show when a project is selected */}
+      {projectId && (
+        <SDKSidebar
+          collapsed={sidebarCollapsed}
+          onCollapsedChange={handleCollapsedChange}
+        />
+      )}
 
       {/* Main Content - dynamic margin based on sidebar state */}
-      <div className={`${sidebarCollapsed ? 'ml-16' : 'ml-64'} flex flex-col min-h-screen transition-all duration-300`}>
-        {/* Header */}
-        <SDKHeader sidebarCollapsed={sidebarCollapsed} />
+      <div className={`${projectId ? (sidebarCollapsed ? 'ml-16' : 'ml-64') : ''} flex flex-col min-h-screen transition-all duration-300`}>
+        {/* Header — only show when a project is selected */}
+        {projectId && <SDKHeader sidebarCollapsed={sidebarCollapsed} />}
 
         {/* Page Content */}
         <main className="flex-1 p-6">{children}</main>
@@ -191,10 +210,10 @@ function SDKInnerLayout({ children }: { children: React.ReactNode }) {
       {isCommandBarOpen && <CommandBar onClose={() => setCommandBarOpen(false)} />}
 
       {/* Pipeline Sidebar (FAB on mobile/tablet, fixed on desktop xl+) */}
-      <SDKPipelineSidebar />
+      {projectId && <SDKPipelineSidebar />}
 
       {/* Compliance Advisor Widget */}
-      <ComplianceAdvisorWidget currentStep={currentStep} />
+      {projectId && <ComplianceAdvisorWidget currentStep={currentStep} />}
     </div>
   )
 }
@@ -208,8 +227,11 @@ export default function SDKRootLayout({
 }: {
   children: React.ReactNode
 }) {
+  const searchParams = useSearchParams()
+  const projectId = searchParams.get('project') || undefined
+
   return (
-    <SDKProvider enableBackendSync={true}>
+    <SDKProvider enableBackendSync={true} projectId={projectId}>
       <SDKInnerLayout>{children}</SDKInnerLayout>
     </SDKProvider>
   )