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/lib/sdk/sync.ts

@@ -59,6 +59,7 @@ const DEFAULT_MAX_RETRIES = 3
 export class StateSyncManager {
   private apiClient: SDKApiClient
   private tenantId: string
+  private projectId: string | undefined
   private options: Required<SyncOptions>
   private callbacks: SyncCallbacks
   private syncState: SyncState
@@ -71,10 +72,12 @@ export class StateSyncManager {
     apiClient: SDKApiClient,
     tenantId: string,
     options: SyncOptions = {},
-    callbacks: SyncCallbacks = {}
+    callbacks: SyncCallbacks = {},
+    projectId?: string
   ) {
     this.apiClient = apiClient
     this.tenantId = tenantId
+    this.projectId = projectId
     this.callbacks = callbacks
     this.options = {
       debounceMs: options.debounceMs ?? DEFAULT_DEBOUNCE_MS,
@@ -105,7 +108,10 @@ export class StateSyncManager {
     }
 
     try {
-      this.broadcastChannel = new BroadcastChannel(`${SYNC_CHANNEL}-${this.tenantId}`)
+      const channelName = this.projectId
+        ? `${SYNC_CHANNEL}-${this.tenantId}-${this.projectId}`
+        : `${SYNC_CHANNEL}-${this.tenantId}`
+      this.broadcastChannel = new BroadcastChannel(channelName)
       this.broadcastChannel.onmessage = this.handleBroadcastMessage.bind(this)
     } catch (error) {
       console.warn('BroadcastChannel not available:', error)
@@ -209,7 +215,9 @@ export class StateSyncManager {
   // ---------------------------------------------------------------------------
 
   private getStorageKey(): string {
-    return `${STORAGE_KEY_PREFIX}-${this.tenantId}`
+    return this.projectId
+      ? `${STORAGE_KEY_PREFIX}-${this.tenantId}-${this.projectId}`
+      : `${STORAGE_KEY_PREFIX}-${this.tenantId}`
   }
 
   saveToLocalStorage(state: SDKState): void {
@@ -476,7 +484,8 @@ export function createStateSyncManager(
   apiClient: SDKApiClient,
   tenantId: string,
   options?: SyncOptions,
-  callbacks?: SyncCallbacks
+  callbacks?: SyncCallbacks,
+  projectId?: string
 ): StateSyncManager {
-  return new StateSyncManager(apiClient, tenantId, options, callbacks)
+  return new StateSyncManager(apiClient, tenantId, options, callbacks, projectId)
 }