feat: Mini-Apps registry, Stammdaten backend persistence, bank accounts

- Register 6 mini-apps in kommunikation plugin (contact_picker, file_share,
  calendar_invite, mail_forward, ai_search, task_create)
- Connect AdressenTab to backend API (GET/POST/PATCH/DELETE /addresses)
- Create BankAccount model, schema, service, routes + migration 0033
- Connect KontenTab to backend API (GET/POST/PATCH/DELETE /bank-accounts)
- AI tools already working: 7 tools registered (hybrid_search, get_contact_mails, etc.)

app/routes/__init__.py

@@ -3,6 +3,7 @@
 from app.routes import (
     addresses,  # noqa: F401
     ai_copilot,  # noqa: F401
+    bank_accounts,  # noqa: F401
     audit,  # noqa: F401
     auth,  # noqa: F401
     contacts,  # noqa: F401

app/routes/bank_accounts.py

@@ -0,0 +1,85 @@
+"""Bank account routes — list, create, update, delete with tenant isolation."""
+
+from __future__ import annotations
+
+import uuid
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.core.db import get_db
+from app.deps import require_permission
+from app.schemas.bank_account import BankAccountCreate, BankAccountUpdate
+from app.services import bank_account_service
+
+router = APIRouter(prefix="/api/v1/bank-accounts", tags=["bank-accounts"])
+
+
+@router.get("")
+async def list_bank_accounts(
+    db: AsyncSession = Depends(get_db),
+    current_user: dict = Depends(require_permission("bank-accounts:read")),
+):
+    """List all bank accounts for the current tenant."""
+    tenant_id = uuid.UUID(current_user["tenant_id"])
+    return await bank_account_service.list_bank_accounts(db, tenant_id)
+
+
+@router.post("", status_code=status.HTTP_201_CREATED)
+async def create_bank_account(
+    body: BankAccountCreate,
+    db: AsyncSession = Depends(get_db),
+    current_user: dict = Depends(require_permission("bank-accounts:write")),
+):
+    """Create a new bank account."""
+    tenant_id = uuid.UUID(current_user["tenant_id"])
+    user_id = uuid.UUID(current_user["user_id"])
+
+    data = body.model_dump()
+    try:
+        return await bank_account_service.create_bank_account(db, tenant_id, user_id, data)
+    except ValueError as exc:
+        raise HTTPException(400, detail={"detail": str(exc), "code": "invalid_value"}) from exc
+
+
+@router.patch("/{account_id}")
+async def update_bank_account(
+    account_id: str,
+    body: BankAccountUpdate,
+    db: AsyncSession = Depends(get_db),
+    current_user: dict = Depends(require_permission("bank-accounts:write")),
+):
+    """Update a bank account."""
+    tenant_id = uuid.UUID(current_user["tenant_id"])
+    user_id = uuid.UUID(current_user["user_id"])
+
+    try:
+        aid = uuid.UUID(account_id)
+    except ValueError:
+        raise HTTPException(400, detail={"detail": "Invalid account_id", "code": "invalid_id"}) from None
+
+    data = body.model_dump(exclude_unset=True)
+    result = await bank_account_service.update_bank_account(db, tenant_id, user_id, aid, data)
+    if result is None:
+        raise HTTPException(404, detail={"detail": "Bank account not found", "code": "not_found"})
+    return result
+
+
+@router.delete("/{account_id}", status_code=status.HTTP_204_NO_CONTENT)
+async def delete_bank_account(
+    account_id: str,
+    db: AsyncSession = Depends(get_db),
+    current_user: dict = Depends(require_permission("bank-accounts:write")),
+):
+    """Soft-delete a bank account."""
+    tenant_id = uuid.UUID(current_user["tenant_id"])
+    user_id = uuid.UUID(current_user["user_id"])
+
+    try:
+        aid = uuid.UUID(account_id)
+    except ValueError:
+        raise HTTPException(400, detail={"detail": "Invalid account_id", "code": "invalid_id"}) from None
+
+    deleted = await bank_account_service.delete_bank_account(db, tenant_id, user_id, aid)
+    if not deleted:
+        raise HTTPException(404, detail={"detail": "Bank account not found", "code": "not_found"})