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/api/sdk/v1/projects/[projectId]/route.ts

@@ -0,0 +1,120 @@
+import { NextRequest, NextResponse } from 'next/server'
+
+const BACKEND_URL = process.env.BACKEND_URL || 'http://backend-compliance:8002'
+
+/**
+ * Proxy: GET /api/sdk/v1/projects/{projectId} → Backend
+ */
+export async function GET(
+  request: NextRequest,
+  { params }: { params: Promise<{ projectId: string }> }
+) {
+  try {
+    const { projectId } = await params
+    const tenantId = request.headers.get('X-Tenant-ID') ||
+      new URL(request.url).searchParams.get('tenant_id') || ''
+
+    const response = await fetch(
+      `${BACKEND_URL}/api/v1/projects/${projectId}?tenant_id=${encodeURIComponent(tenantId)}`,
+      {
+        headers: { 'X-Tenant-ID': tenantId },
+      }
+    )
+
+    if (!response.ok) {
+      const errorText = await response.text()
+      return NextResponse.json(
+        { error: 'Backend error', details: errorText },
+        { status: response.status }
+      )
+    }
+
+    return NextResponse.json(await response.json())
+  } catch (error) {
+    console.error('Failed to get project:', error)
+    return NextResponse.json(
+      { error: 'Failed to connect to backend' },
+      { status: 503 }
+    )
+  }
+}
+
+/**
+ * Proxy: PATCH /api/sdk/v1/projects/{projectId} → Backend
+ */
+export async function PATCH(
+  request: NextRequest,
+  { params }: { params: Promise<{ projectId: string }> }
+) {
+  try {
+    const { projectId } = await params
+    const body = await request.json()
+    const tenantId = body.tenant_id || request.headers.get('X-Tenant-ID') || ''
+
+    const response = await fetch(
+      `${BACKEND_URL}/api/v1/projects/${projectId}?tenant_id=${encodeURIComponent(tenantId)}`,
+      {
+        method: 'PATCH',
+        headers: {
+          'Content-Type': 'application/json',
+          'X-Tenant-ID': tenantId,
+        },
+        body: JSON.stringify(body),
+      }
+    )
+
+    if (!response.ok) {
+      const errorText = await response.text()
+      return NextResponse.json(
+        { error: 'Backend error', details: errorText },
+        { status: response.status }
+      )
+    }
+
+    return NextResponse.json(await response.json())
+  } catch (error) {
+    console.error('Failed to update project:', error)
+    return NextResponse.json(
+      { error: 'Failed to connect to backend' },
+      { status: 503 }
+    )
+  }
+}
+
+/**
+ * Proxy: DELETE /api/sdk/v1/projects/{projectId} → Backend (soft delete)
+ */
+export async function DELETE(
+  request: NextRequest,
+  { params }: { params: Promise<{ projectId: string }> }
+) {
+  try {
+    const { projectId } = await params
+    const tenantId = request.headers.get('X-Tenant-ID') ||
+      new URL(request.url).searchParams.get('tenant_id') || ''
+
+    const response = await fetch(
+      `${BACKEND_URL}/api/v1/projects/${projectId}?tenant_id=${encodeURIComponent(tenantId)}`,
+      {
+        method: 'DELETE',
+        headers: { 'X-Tenant-ID': tenantId },
+      }
+    )
+
+    if (!response.ok) {
+      const errorText = await response.text()
+      return NextResponse.json(
+        { error: 'Backend error', details: errorText },
+        { status: response.status }
+      )
+    }
+
+    return NextResponse.json(await response.json())
+  } catch (error) {
+    console.error('Failed to archive project:', error)
+    return NextResponse.json(
+      { error: 'Failed to connect to backend' },
+      { status: 503 }
+    )
+  }
+}

admin-compliance/app/api/sdk/v1/projects/route.ts

@@ -0,0 +1,75 @@
+import { NextRequest, NextResponse } from 'next/server'
+
+const BACKEND_URL = process.env.BACKEND_URL || 'http://backend-compliance:8002'
+
+/**
+ * Proxy: GET /api/sdk/v1/projects → Backend GET /api/v1/projects
+ */
+export async function GET(request: NextRequest) {
+  try {
+    const { searchParams } = new URL(request.url)
+    const tenantId = searchParams.get('tenant_id') || request.headers.get('X-Tenant-ID') || ''
+    const includeArchived = searchParams.get('include_archived') || 'false'
+
+    const response = await fetch(
+      `${BACKEND_URL}/api/v1/projects?tenant_id=${encodeURIComponent(tenantId)}&include_archived=${includeArchived}`,
+      {
+        headers: { 'X-Tenant-ID': tenantId },
+      }
+    )
+
+    if (!response.ok) {
+      const errorText = await response.text()
+      return NextResponse.json(
+        { error: 'Backend error', details: errorText },
+        { status: response.status }
+      )
+    }
+
+    return NextResponse.json(await response.json())
+  } catch (error) {
+    console.error('Failed to list projects:', error)
+    return NextResponse.json(
+      { error: 'Failed to connect to backend' },
+      { status: 503 }
+    )
+  }
+}
+
+/**
+ * Proxy: POST /api/sdk/v1/projects → Backend POST /api/v1/projects
+ */
+export async function POST(request: NextRequest) {
+  try {
+    const body = await request.json()
+    const tenantId = body.tenant_id || request.headers.get('X-Tenant-ID') || ''
+
+    const response = await fetch(
+      `${BACKEND_URL}/api/v1/projects?tenant_id=${encodeURIComponent(tenantId)}`,
+      {
+        method: 'POST',
+        headers: {
+          'Content-Type': 'application/json',
+          'X-Tenant-ID': tenantId,
+        },
+        body: JSON.stringify(body),
+      }
+    )
+
+    if (!response.ok) {
+      const errorText = await response.text()
+      return NextResponse.json(
+        { error: 'Backend error', details: errorText },
+        { status: response.status }
+      )
+    }
+
+    return NextResponse.json(await response.json(), { status: 201 })
+  } catch (error) {
+    console.error('Failed to create project:', error)
+    return NextResponse.json(
+      { error: 'Failed to connect to backend' },
+      { status: 503 }
+    )
+  }
+}

admin-compliance/app/api/sdk/v1/state/route.ts

@@ -2,17 +2,18 @@ import { NextRequest, NextResponse } from 'next/server'
 import { Pool } from 'pg'
 
 /**
- * SDK State Management API
+ * SDK State Management API (Multi-Project)
  *
- * GET /api/sdk/v1/state?tenantId=xxx - Load state for a tenant
- * POST /api/sdk/v1/state - Save state for a tenant
- * DELETE /api/sdk/v1/state?tenantId=xxx - Clear state for a tenant
+ * GET /api/sdk/v1/state?tenantId=xxx&projectId=yyy - Load state for a tenant+project
+ * POST /api/sdk/v1/state - Save state for a tenant+project
+ * DELETE /api/sdk/v1/state?tenantId=xxx&projectId=yyy - Clear state
  *
  * Features:
  * - Versioning for optimistic locking
  * - Last-Modified headers
  * - ETag support for caching
  * - PostgreSQL persistence (with InMemory fallback)
+ * - projectId support for multi-project architecture
  */
 
 // =============================================================================
@@ -32,25 +33,31 @@ interface StoredState {
 // =============================================================================
 
 interface StateStore {
-  get(tenantId: string): Promise<StoredState | null>
-  save(tenantId: string, state: unknown, userId?: string, expectedVersion?: number): Promise<StoredState>
-  delete(tenantId: string): Promise<boolean>
+  get(tenantId: string, projectId?: string): Promise<StoredState | null>
+  save(tenantId: string, state: unknown, userId?: string, expectedVersion?: number, projectId?: string): Promise<StoredState>
+  delete(tenantId: string, projectId?: string): Promise<boolean>
 }
 
 class InMemoryStateStore implements StateStore {
   private store: Map<string, StoredState> = new Map()
 
-  async get(tenantId: string): Promise<StoredState | null> {
-    return this.store.get(tenantId) || null
+  private key(tenantId: string, projectId?: string): string {
+    return projectId ? `${tenantId}:${projectId}` : tenantId
+  }
+
+  async get(tenantId: string, projectId?: string): Promise<StoredState | null> {
+    return this.store.get(this.key(tenantId, projectId)) || null
   }
 
   async save(
     tenantId: string,
     state: unknown,
     userId?: string,
-    expectedVersion?: number
+    expectedVersion?: number,
+    projectId?: string
   ): Promise<StoredState> {
-    const existing = this.store.get(tenantId)
+    const k = this.key(tenantId, projectId)
+    const existing = this.store.get(k)
 
     if (expectedVersion !== undefined && existing && existing.version !== expectedVersion) {
       const error = new Error('Version conflict') as Error & { status: number }
@@ -72,12 +79,12 @@ class InMemoryStateStore implements StateStore {
       updatedAt: now,
     }
 
-    this.store.set(tenantId, stored)
+    this.store.set(k, stored)
     return stored
   }
 
-  async delete(tenantId: string): Promise<boolean> {
-    return this.store.delete(tenantId)
+  async delete(tenantId: string, projectId?: string): Promise<boolean> {
+    return this.store.delete(this.key(tenantId, projectId))
   }
 }
 
@@ -93,11 +100,26 @@ class PostgreSQLStateStore implements StateStore {
     })
   }
 
-  async get(tenantId: string): Promise<StoredState | null> {
-    const result = await this.pool.query(
-      'SELECT state, version, user_id, created_at, updated_at FROM sdk_states WHERE tenant_id = $1',
-      [tenantId]
-    )
+  async get(tenantId: string, projectId?: string): Promise<StoredState | null> {
+    let result
+    if (projectId) {
+      result = await this.pool.query(
+        'SELECT state, version, user_id, created_at, updated_at FROM sdk_states WHERE tenant_id = $1 AND project_id = $2',
+        [tenantId, projectId]
+      )
+    } else {
+      // Backwards compatibility: find the single active project for this tenant
+      result = await this.pool.query(
+        `SELECT s.state, s.version, s.user_id, s.created_at, s.updated_at
+         FROM sdk_states s
+         LEFT JOIN compliance_projects p ON s.project_id = p.id
+         WHERE s.tenant_id = $1
+           AND (p.status = 'active' OR p.id IS NULL)
+         ORDER BY s.updated_at DESC
+         LIMIT 1`,
+        [tenantId]
+      )
+    }
     if (result.rows.length === 0) return null
     const row = result.rows[0]
     return {
@@ -109,25 +131,71 @@ class PostgreSQLStateStore implements StateStore {
     }
   }
 
-  async save(tenantId: string, state: unknown, userId?: string, expectedVersion?: number): Promise<StoredState> {
+  async save(tenantId: string, state: unknown, userId?: string, expectedVersion?: number, projectId?: string): Promise<StoredState> {
     const now = new Date().toISOString()
     const stateWithTimestamp = {
       ...(state as object),
       lastModified: now,
     }
 
-    // Use UPSERT with version check
-    const result = await this.pool.query(`
-      INSERT INTO sdk_states (tenant_id, user_id, state, version, created_at, updated_at)
-      VALUES ($1, $2, $3::jsonb, 1, NOW(), NOW())
-      ON CONFLICT (tenant_id) DO UPDATE SET
-        state = $3::jsonb,
-        user_id = COALESCE($2, sdk_states.user_id),
-        version = sdk_states.version + 1,
-        updated_at = NOW()
-      WHERE ($4::int IS NULL OR sdk_states.version = $4)
-      RETURNING version, user_id, created_at, updated_at
-    `, [tenantId, userId, JSON.stringify(stateWithTimestamp), expectedVersion ?? null])
+    let result
+
+    if (projectId) {
+      // Multi-project: UPSERT on (tenant_id, project_id)
+      result = await this.pool.query(`
+        INSERT INTO sdk_states (tenant_id, project_id, user_id, state, version, created_at, updated_at)
+        VALUES ($1, $5, $2, $3::jsonb, 1, NOW(), NOW())
+        ON CONFLICT (tenant_id, project_id) DO UPDATE SET
+          state = $3::jsonb,
+          user_id = COALESCE($2, sdk_states.user_id),
+          version = sdk_states.version + 1,
+          updated_at = NOW()
+        WHERE ($4::int IS NULL OR sdk_states.version = $4)
+        RETURNING version, user_id, created_at, updated_at
+      `, [tenantId, userId, JSON.stringify(stateWithTimestamp), expectedVersion ?? null, projectId])
+    } else {
+      // Backwards compatibility: find the single project for this tenant
+      // First try to find an existing project
+      const projectResult = await this.pool.query(
+        `SELECT id FROM compliance_projects WHERE tenant_id = $1 AND status = 'active' ORDER BY created_at ASC LIMIT 1`,
+        [tenantId]
+      )
+
+      if (projectResult.rows.length > 0) {
+        const foundProjectId = projectResult.rows[0].id
+        result = await this.pool.query(`
+          INSERT INTO sdk_states (tenant_id, project_id, user_id, state, version, created_at, updated_at)
+          VALUES ($1, $5, $2, $3::jsonb, 1, NOW(), NOW())
+          ON CONFLICT (tenant_id, project_id) DO UPDATE SET
+            state = $3::jsonb,
+            user_id = COALESCE($2, sdk_states.user_id),
+            version = sdk_states.version + 1,
+            updated_at = NOW()
+          WHERE ($4::int IS NULL OR sdk_states.version = $4)
+          RETURNING version, user_id, created_at, updated_at
+        `, [tenantId, userId, JSON.stringify(stateWithTimestamp), expectedVersion ?? null, foundProjectId])
+      } else {
+        // No project exists — create a default one
+        const newProject = await this.pool.query(
+          `INSERT INTO compliance_projects (tenant_id, name, customer_type, status)
+           VALUES ($1, 'Projekt 1', 'new', 'active')
+           RETURNING id`,
+          [tenantId]
+        )
+        const newProjectId = newProject.rows[0].id
+        result = await this.pool.query(`
+          INSERT INTO sdk_states (tenant_id, project_id, user_id, state, version, created_at, updated_at)
+          VALUES ($1, $5, $2, $3::jsonb, 1, NOW(), NOW())
+          ON CONFLICT (tenant_id, project_id) DO UPDATE SET
+            state = $3::jsonb,
+            user_id = COALESCE($2, sdk_states.user_id),
+            version = sdk_states.version + 1,
+            updated_at = NOW()
+          WHERE ($4::int IS NULL OR sdk_states.version = $4)
+          RETURNING version, user_id, created_at, updated_at
+        `, [tenantId, userId, JSON.stringify(stateWithTimestamp), expectedVersion ?? null, newProjectId])
+      }
+    }
 
     if (result.rows.length === 0) {
       const error = new Error('Version conflict') as Error & { status: number }
@@ -145,11 +213,19 @@ class PostgreSQLStateStore implements StateStore {
     }
   }
 
-  async delete(tenantId: string): Promise<boolean> {
-    const result = await this.pool.query(
-      'DELETE FROM sdk_states WHERE tenant_id = $1',
-      [tenantId]
-    )
+  async delete(tenantId: string, projectId?: string): Promise<boolean> {
+    let result
+    if (projectId) {
+      result = await this.pool.query(
+        'DELETE FROM sdk_states WHERE tenant_id = $1 AND project_id = $2',
+        [tenantId, projectId]
+      )
+    } else {
+      result = await this.pool.query(
+        'DELETE FROM sdk_states WHERE tenant_id = $1',
+        [tenantId]
+      )
+    }
     return (result.rowCount ?? 0) > 0
   }
 }
@@ -186,6 +262,7 @@ export async function GET(request: NextRequest) {
   try {
     const { searchParams } = new URL(request.url)
     const tenantId = searchParams.get('tenantId')
+    const projectId = searchParams.get('projectId') || undefined
 
     if (!tenantId) {
       return NextResponse.json(
@@ -194,7 +271,7 @@ export async function GET(request: NextRequest) {
       )
     }
 
-    const stored = await stateStore.get(tenantId)
+    const stored = await stateStore.get(tenantId, projectId)
 
     if (!stored) {
       return NextResponse.json(
@@ -216,6 +293,7 @@ export async function GET(request: NextRequest) {
         success: true,
         data: {
           tenantId,
+          projectId: projectId || null,
           state: stored.state,
           version: stored.version,
           lastModified: stored.updatedAt,
@@ -241,7 +319,7 @@ export async function GET(request: NextRequest) {
 export async function POST(request: NextRequest) {
   try {
     const body = await request.json()
-    const { tenantId, state, version } = body
+    const { tenantId, state, version, projectId } = body
 
     if (!tenantId) {
       return NextResponse.json(
@@ -261,7 +339,7 @@ export async function POST(request: NextRequest) {
     const ifMatch = request.headers.get('If-Match')
     const expectedVersion = ifMatch ? parseInt(ifMatch, 10) : version
 
-    const stored = await stateStore.save(tenantId, state, body.userId, expectedVersion)
+    const stored = await stateStore.save(tenantId, state, body.userId, expectedVersion, projectId || undefined)
 
     const etag = generateETag(stored.version, stored.updatedAt)
 
@@ -270,6 +348,7 @@ export async function POST(request: NextRequest) {
         success: true,
         data: {
           tenantId,
+          projectId: projectId || null,
           state: stored.state,
           version: stored.version,
           lastModified: stored.updatedAt,
@@ -309,6 +388,7 @@ export async function DELETE(request: NextRequest) {
   try {
     const { searchParams } = new URL(request.url)
     const tenantId = searchParams.get('tenantId')
+    const projectId = searchParams.get('projectId') || undefined
 
     if (!tenantId) {
       return NextResponse.json(
@@ -317,7 +397,7 @@ export async function DELETE(request: NextRequest) {
       )
     }
 
-    const deleted = await stateStore.delete(tenantId)
+    const deleted = await stateStore.delete(tenantId, projectId)
 
     if (!deleted) {
       return NextResponse.json(