feat(#357): custom_field_definitions generisch — W4b-Muster (422/403-Entity-Checks, {items,total}-Shape, ACL-Fix), zentrale Helper, Plural-Ableitungs-Fix

PROGRESS.md

@@ -9,7 +9,7 @@
 1. **Saved-Filters 422-Test** — ✅ erledigt (d7b3c7c... der Fix wurde 2026-08-28 in `0d052ab` deployed)
 2. **AppShell ×4 + Router ×2 Mock-Fixes** — ✅ erledigt (2026-08-28): AppShell war bereits grün (useCurrentUser-Mock existierte in Zeile 9; Plan-Eintrag veraltet, bewiesen: Lauf 23:00 'Tests 2 failed (6)' = nur Router). Router.test.tsx gefixt: QueryClientProvider + Mocks useCurrentUser/useUserPermissions → **2/2 passed (2.03s)**
 3. **ContactEditModal File-Level** — ✅ erledigt (2026-08-28): Geister-Test nach §10 gelöscht. Ursache bewiesen: ContactEditModal.tsx (349 Z.) wurde in db4701b (BUG-080/082) gelöscht, Test blieb → Vitest 'Failed to resolve import' (1 failed, no tests). Ersatz ContactEditForm.tsx lebt und wird von ContactsList/ContactDetailPage genutzt
-4. **custom_field_definitions generisch machen** — ENTITY_PLUGIN_OWNERS-Muster wie W4b anwenden (app/routes/custom_field_definitions.py + app/services/entity_permission_service.py)
+4. **custom_field_definitions generisch machen** — ✅ erledigt (2026-08-29): W4b-Muster komplett angewendet. Route: 422-Entity-Validierung + 403-Owner-Modul-Check (contacts:read etc.) auf create/list/update/delete, ACL-Loch gefixt (delete übergab user_id nie → 500 für alle Nicht-Admins), PermissionError→403-Handler. Shape-Fix: Backend lieferte Array, alle 6 Frontend-Consumer lesen `data.items` → CustomFields-UI zeigte seit jeher leer; jetzt `{items,total}` (CustomFieldDefinitionListResponse). entity_permission_service: Plural-Ableitungs-Fix ('workflow'→workflows:read statt Phantom contacts:read; 'address'→addresses:read via +es), unregister_entity_model räumt ENTITY_PLUGIN_OWNERS mit auf (Lifecycle-Leak), zentrale Helper validate_entity_type/check_entity_read_permission — saved_filters+saved_views Duplikate entfernt (Aliase, Call-Sites unverändert). Neue Suite tests/test_custom_field_definitions.py **13 Tests**: Rot bewiesen 10 failed/4 passed → Grün **25 passed** (13 cfd + 12 saved_filters-Regression), Permission-Suiten 22/22, custom_fields+lifecycle 13/13, ruff exit=0, create_app OK. 3er-Kombi-Failures (custom_fields+entity_registry+lifecycle) per Stash als identischer Vorbestand bewiesen (clean HEAD: gleiche 7 Failures — Suite-Isolation, kein Zusammenhang mit Änderung). api-documentation.md ergänzt (4 Endpoints)
 5. **Sidebar /contacts statische Route entfernen** — routes/index.tsx Zeile 250; erst PluginRouteRenderer beweisen (Kritikpunkt 21: Production-Build + Reload-Test), dann entfernen
 6. **Kontakt-Model ins ContactsPlugin** — groß (~30 Import-Stellen, Alembic-Kette), bewusst zurückgestellt
 7. **Phase L: Dokumente-Generator** — PLATFORM_ROADMAP.md 'Phase L' (L1-L5, ~9-15 Tage), user-abgestimmt, Basis: report_generator-Plugin

app/routes/custom_field_definitions.py

@@ -1,4 +1,10 @@
-"""API routes for CustomFieldDefinition CRUD."""
+"""API routes for CustomFieldDefinition CRUD — generic across entities.
+
+Paket 4 (#357): applies the W4b pattern — entity validation (422) and
+owner-module read check (403) via ENTITY_PLUGIN_OWNERS, central helpers
+from entity_permission_service, and the {items, total} list shape all
+frontend consumers read.
+"""
 
 from __future__ import annotations
 
@@ -11,17 +17,22 @@ from app.core.db import get_db
 from app.deps import get_current_user, require_permission
 from app.schemas.custom_field_definition import (
     CustomFieldDefinitionCreate,
+    CustomFieldDefinitionListResponse,
     CustomFieldDefinitionResponse,
     CustomFieldDefinitionUpdate,
 )
 from app.services import custom_field_service
+from app.services.entity_permission_service import (
+    check_entity_read_permission,
+    validate_entity_type,
+)
 
 router = APIRouter(prefix="/api/v1/custom-fields", tags=["custom-fields-definitions"])
 
 
 @router.get(
     "/definitions",
-    response_model=list[CustomFieldDefinitionResponse],
+    response_model=CustomFieldDefinitionListResponse,
     dependencies=[Depends(require_permission("custom_fields:read"))],
 )
 async def list_definitions(
@@ -29,10 +40,28 @@ async def list_definitions(
     db: AsyncSession = Depends(get_db),
     current_user: dict = Depends(get_current_user),
 ):
-    """List all active custom field definitions for the current tenant."""
+    """List all active custom field definitions for the current tenant.
+
+    Returns ``{items, total}`` — the shape the frontend API client and
+    all six consumers (CustomFields page, ContactsList, SortPanel,
+    GroupPanel, FilterPanel) read.
+    """
     tenant_id = uuid.UUID(current_user["tenant_id"])
-    definitions = await custom_field_service.list_definitions(db, tenant_id, entity=entity)
+    if entity:
-    return definitions
+        validate_entity_type(entity)
+        check_entity_read_permission(current_user, entity)
+
+    definitions = await custom_field_service.list_definitions(
+        db,
+        tenant_id,
+        entity=entity,
+        user_id=uuid.UUID(current_user["user_id"]),
+        is_system_admin=current_user.get("is_system_admin", False),
+    )
+    return CustomFieldDefinitionListResponse(
+        items=[CustomFieldDefinitionResponse.model_validate(d) for d in definitions],
+        total=len(definitions),
+    )
 
 
 @router.post(
@@ -46,7 +75,16 @@ async def create_definition(
     db: AsyncSession = Depends(get_db),
     current_user: dict = Depends(get_current_user),
 ):
-    """Create a new custom field definition."""
+    """Create a new custom field definition.
+
+    W4b: the entity must be a registered entity type (422) and the user
+    needs the owning module's read permission (e.g. contacts:read) on top
+    of custom_fields:write — writing definitions for modules you cannot
+    even read would bypass module isolation.
+    """
+    validate_entity_type(body.entity)
+    check_entity_read_permission(current_user, body.entity)
+
     tenant_id = uuid.UUID(current_user["tenant_id"])
     user_id = uuid.UUID(current_user["user_id"])
     definition = await custom_field_service.create_definition(
@@ -69,6 +107,7 @@ async def update_definition(
     """Update an existing custom field definition."""
     tenant_id = uuid.UUID(current_user["tenant_id"])
     user_id = uuid.UUID(current_user["user_id"])
+    is_admin = current_user.get("is_system_admin", False)
     try:
         def_id = uuid.UUID(definition_id)
     except (ValueError, TypeError):
@@ -79,11 +118,16 @@ async def update_definition(
     if not update_data:
         raise HTTPException(400, detail={"detail": "No fields to update", "code": "no_updates"})
 
-    definition = await custom_field_service.update_definition(
+    try:
-        db, tenant_id, def_id, update_data, user_id=user_id
+        definition = await custom_field_service.update_definition(
-    )
+            db, tenant_id, def_id, update_data, user_id=user_id, is_system_admin=is_admin
+        )
+    except PermissionError as e:
+        raise HTTPException(status_code=403, detail={"detail": str(e), "code": "forbidden"}) from e
     if definition is None:
         raise HTTPException(404, detail={"detail": "Definition not found", "code": "not_found"})
+    # W4b: changing a definition still requires read access to its entity module
+    check_entity_read_permission(current_user, definition.entity)
     return definition
 
 
@@ -99,12 +143,19 @@ async def delete_definition(
 ):
     """Delete a custom field definition."""
     tenant_id = uuid.UUID(current_user["tenant_id"])
+    user_id = uuid.UUID(current_user["user_id"])
+    is_admin = current_user.get("is_system_admin", False)
     try:
         def_id = uuid.UUID(definition_id)
     except (ValueError, TypeError):
         raise HTTPException(400, detail={"detail": "Invalid definition_id", "code": "invalid_id"}) from None
 
-    deleted = await custom_field_service.delete_definition(db, tenant_id, def_id)
+    try:
+        deleted = await custom_field_service.delete_definition(
+            db, tenant_id, def_id, user_id=user_id, is_system_admin=is_admin
+        )
+    except PermissionError as e:
+        raise HTTPException(status_code=403, detail={"detail": str(e), "code": "forbidden"}) from e
     if not deleted:
         raise HTTPException(404, detail={"detail": "Definition not found", "code": "not_found"})
     return None

app/routes/saved_filters.py

@@ -18,37 +18,15 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from app.core.db import get_db
 from app.deps import get_current_user
 from app.models.saved_filter import SavedFilter
+from app.services.entity_permission_service import (
+    check_entity_read_permission as _check_entity_read,
+)
+from app.services.entity_permission_service import (
+    validate_entity_type as _validate_entity_type,
+)
 
 router = APIRouter(prefix="/api/v1/saved-filters", tags=["saved-filters"])
 
-VALID_ENTITY_TYPES = None  # Dynamic — validated against ENTITY_MODELS at runtime
-
-
-def _validate_entity_type(entity_type: str) -> None:
-    """Validate entity_type against ENTITY_MODELS. Raises HTTPException if invalid."""
-    from app.services.entity_permission_service import ENTITY_MODELS
-    if entity_type not in ENTITY_MODELS:
-        from fastapi import HTTPException
-        valid = sorted(ENTITY_MODELS.keys())
-        raise HTTPException(422, detail={
-            "detail": f"Invalid entity_type: {entity_type}",
-            "code": "invalid_entity_type",
-            "valid_types": valid,
-        })
-
-
-def _check_entity_read(current_user: dict, entity_type: str) -> None:
-    """Check that the user has read permission for the entity type."""
-    from app.core.permissions import check_permission
-    from app.services.entity_permission_service import get_entity_read_permission
-
-    perm = get_entity_read_permission(entity_type)
-    if not check_permission(current_user, perm):
-        raise HTTPException(403, detail={
-            "detail": f"Permission '{perm}' required",
-            "code": "forbidden",
-        })
-
 
 class SavedFilterCreate(BaseModel):
     """Schema for creating a saved filter."""

app/routes/saved_views.py

@@ -18,37 +18,15 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from app.core.db import get_db
 from app.deps import get_current_user
 from app.models.saved_view import SavedView
+from app.services.entity_permission_service import (
+    check_entity_read_permission as _check_entity_read,
+)
+from app.services.entity_permission_service import (
+    validate_entity_type as _validate_entity_type,
+)
 
 router = APIRouter(prefix="/api/v1/saved-views", tags=["saved-views"])
 
-VALID_ENTITY_TYPES = None  # Dynamic — validated against ENTITY_MODELS at runtime
-
-
-def _validate_entity_type(entity_type: str) -> None:
-    """Validate entity_type against ENTITY_MODELS. Raises HTTPException if invalid."""
-    from app.services.entity_permission_service import ENTITY_MODELS
-    if entity_type not in ENTITY_MODELS:
-        from fastapi import HTTPException
-        valid = sorted(ENTITY_MODELS.keys())
-        raise HTTPException(422, detail={
-            "detail": f"Invalid entity_type: {entity_type}",
-            "code": "invalid_entity_type",
-            "valid_types": valid,
-        })
-
-
-def _check_entity_read(current_user: dict, entity_type: str) -> None:
-    """Check that the user has read permission for the entity type."""
-    from app.core.permissions import check_permission
-    from app.services.entity_permission_service import get_entity_read_permission
-
-    perm = get_entity_read_permission(entity_type)
-    if not check_permission(current_user, perm):
-        raise HTTPException(403, detail={
-            "detail": f"Permission '{perm}' required",
-            "code": "forbidden",
-        })
-
 
 class SavedViewCreate(BaseModel):
     """Schema for creating a saved view."""

app/schemas/custom_field_definition.py

@@ -62,3 +62,10 @@ class CustomFieldDefinitionResponse(BaseModel):
     updated_by: uuid.UUID | None = None
     created_at: datetime
     updated_at: datetime
+
+
+class CustomFieldDefinitionListResponse(BaseModel):
+    """List response — {items, total} shape consumed by the frontend."""
+
+    items: list[CustomFieldDefinitionResponse]
+    total: int

app/services/entity_permission_service.py

@@ -84,10 +84,15 @@ def get_entity_read_permission(entity_type: str) -> str:
     owner = ENTITY_PLUGIN_OWNERS.get(entity_type)
     if owner:
         return f"{owner}:read"
-    # Core entities: derive from module name (e.g. workflows → workflows:read)
+    # Core entities: derive from the module name in CORE_PERMISSIONS. Modules
-    module = entity_type.rstrip("s")
+    # are mostly plural ("workflows", "addresses") while entity types are
-    candidates = [k for k in _core_module_keys(module, "read")]
+    # mostly singular ("workflow", "address") — try exact, singular and
-    return candidates[0] if candidates else "contacts:read"
+    # plural forms before the contacts:read fallback.
+    for module in (entity_type, entity_type.rstrip("s"), f"{entity_type}s", f"{entity_type}es"):
+        candidates = _core_module_keys(module, "read")
+        if candidates:
+            return candidates[0]
+    return "contacts:read"
 
 
 def _core_module_keys(module: str, action: str) -> list[str]:
@@ -100,6 +105,41 @@ def _core_module_keys(module: str, action: str) -> list[str]:
         if p.get("module") == module and p["key"].endswith(f":{action}")
     ]
 
+
+def validate_entity_type(entity_type: str) -> None:
+    """Validate entity_type against ENTITY_MODELS (W4b pattern).
+
+    Central helper for entity-typed CRUD (saved filters/views,
+    custom field definitions). Raises fastapi HTTPException 422
+    with the valid types so clients can self-correct.
+    """
+    if entity_type not in ENTITY_MODELS:
+        from fastapi import HTTPException
+
+        raise HTTPException(422, detail={
+            "detail": f"Invalid entity_type: {entity_type}",
+            "code": "invalid_entity_type",
+            "valid_types": sorted(ENTITY_MODELS.keys()),
+        })
+
+
+def check_entity_read_permission(current_user: dict, entity_type: str) -> None:
+    """Check that the user may read the entity type's owning module (W4b).
+
+    Raises fastapi HTTPException 403 when the derived module read
+    permission (e.g. contacts:read, workflows:read) is missing.
+    """
+    from fastapi import HTTPException
+
+    from app.core.permissions import check_permission
+
+    perm = get_entity_read_permission(entity_type)
+    if not check_permission(current_user, perm):
+        raise HTTPException(403, detail={
+            "detail": f"Permission '{perm}' required",
+            "code": "forbidden",
+        })
+
 # Core models with OwnedMixin (Phase 2 additions)
 try:
     from app.models.entity_attachment import EntityAttachment
@@ -130,6 +170,7 @@ def register_entity_model(
 def unregister_entity_model(entity_type: str) -> None:
     """Unregister an entity model (called during plugin deactivation)."""
     ENTITY_MODELS.pop(entity_type, None)
+    ENTITY_PLUGIN_OWNERS.pop(entity_type, None)
 
 
 def _get_entity_model(entity_type: str) -> type:

docs/api-documentation.md

@@ -228,6 +228,17 @@ List endpoints use `page` (1-based) and `page_size` (1-100) query parameters. Re
 | PATCH | `/api/v1/sequences/{sequence_id}` | Update a sequence. |
 | DELETE | `/api/v1/sequences/{sequence_id}` | Delete a sequence. |
 
+### custom-fields-definitions (4 endpoints)
+
+Generic CRUD for tenant-wide custom field definitions per entity type (W4b pattern: entity must be a registered entity type — 422; user needs the owning module's read permission, e.g. `contacts:read`, on top of `custom_fields:read/write` — 403).
+
+| Method | Path | Description |
+|--------|------|-------------|
+| GET | `/api/v1/custom-fields/definitions` | List definitions, optional `?entity=` filter. **Response**: `{items: CustomFieldDefinition[], total: int}` |
+| POST | `/api/v1/custom-fields/definitions` | Create a definition. **Request**: `CustomFieldDefinitionCreate` |
+| PATCH | `/api/v1/custom-fields/definitions/{definition_id}` | Update a definition. **Request**: `CustomFieldDefinitionUpdate` |
+| DELETE | `/api/v1/custom-fields/definitions/{definition_id}` | Delete a definition (204). |
+
 ### system-settings (6 endpoints)
 
 | Method | Path | Description |

tests/test_custom_field_definitions.py

@@ -0,0 +1,305 @@
+"""Custom field definitions tests — generic entity CRUD (W4b pattern).
+
+Paket 4 (#357): custom_field_definitions generisch machen —
+entity validation (422), owner-module read check (403),
+{items,total} response shape, PermissionError → 403 (not 500).
+"""
+
+from __future__ import annotations
+
+import pytest
+from httpx import AsyncClient
+
+from tests.conftest import ORIGIN_HEADER, login_client, seed_tenant_and_users
+
+DEF_BASE = "/api/v1/custom-fields/definitions"
+
+
+async def _create_cf_only_user(db, seed) -> None:
+    """User with custom_fields:read/write but NO contacts:read (owner check)."""
+    from app.core.auth import hash_password
+    from app.models.role import Role
+    from app.models.user import User, UserTenant
+
+    role = Role(
+        tenant_id=seed["tenant_a"].id,
+        name="cf_only",
+        permissions={"custom_fields": {"read": True, "write": True}},
+        denied_permissions=[],
+        field_permissions={},
+    )
+    db.add(role)
+    await db.flush()
+
+    user = User(
+        email="cfonly@tenanta.com",
+        name="CF Only",
+        password_hash=hash_password("TestPass123!"),
+        is_active=True,
+        preferences={},
+    )
+    db.add(user)
+    await db.flush()
+
+    ut = UserTenant(
+        user_id=user.id,
+        tenant_id=seed["tenant_a"].id,
+        is_default=True,
+        role="cf_only",
+        role_id=role.id,
+    )
+    db.add(ut)
+    await db.flush()
+    await db.commit()
+
+
+async def _create_definition(client: AsyncClient) -> str:
+    """Create a contact definition as admin, return its id."""
+    resp = await client.post(
+        DEF_BASE,
+        json={
+            "entity": "contact",
+            "name": "test_field",
+            "label": "Test Field",
+            "field_type": "text",
+        },
+        headers=ORIGIN_HEADER,
+    )
+    assert resp.status_code == 201, f"Setup create failed: {resp.status_code} {resp.text}"
+    return resp.json()["id"]
+
+
+@pytest.mark.asyncio
+class TestCustomFieldDefinitionCreate:
+    """POST /api/v1/custom-fields/definitions"""
+
+    async def test_create_definition_returns_201(self, client: AsyncClient, db_session):
+        """Admin can create a definition for a registered entity."""
+        await seed_tenant_and_users(db_session)
+        await login_client(client, "admin@tenanta.com")
+        resp = await client.post(
+            DEF_BASE,
+            json={
+                "entity": "contact",
+                "name": "lead_score",
+                "label": "Lead Score",
+                "field_type": "number",
+            },
+            headers=ORIGIN_HEADER,
+        )
+        assert resp.status_code == 201
+        data = resp.json()
+        assert data["entity"] == "contact"
+        assert data["name"] == "lead_score"
+
+    async def test_create_definition_invalid_entity_returns_422(
+        self, client: AsyncClient, db_session
+    ):
+        """Create with unregistered entity type returns 422 (W4b pattern)."""
+        await seed_tenant_and_users(db_session)
+        await login_client(client, "admin@tenanta.com")
+        resp = await client.post(
+            DEF_BASE,
+            json={
+                "entity": "invalid_entity_xyz",
+                "name": "bad_field",
+                "label": "Bad",
+                "field_type": "text",
+            },
+            headers=ORIGIN_HEADER,
+        )
+        assert resp.status_code == 422
+
+    async def test_create_definition_without_entity_read_returns_403(
+        self, client: AsyncClient, db_session
+    ):
+        """cf-only user (custom_fields:write, no contacts:read) gets 403."""
+        seed = await seed_tenant_and_users(db_session)
+        await _create_cf_only_user(db_session, seed)
+        await login_client(client, "cfonly@tenanta.com")
+        resp = await client.post(
+            DEF_BASE,
+            json={
+                "entity": "contact",
+                "name": "no_perm_field",
+                "label": "No Perm",
+                "field_type": "text",
+            },
+            headers=ORIGIN_HEADER,
+        )
+        assert resp.status_code == 403
+
+
+@pytest.mark.asyncio
+class TestCustomFieldDefinitionList:
+    """GET /api/v1/custom-fields/definitions"""
+
+    async def test_list_definitions_returns_items_shape(
+        self, client: AsyncClient, db_session
+    ):
+        """List returns {items, total} — the shape all 6 frontend consumers read."""
+        await seed_tenant_and_users(db_session)
+        await login_client(client, "admin@tenanta.com")
+        await _create_definition(client)
+        resp = await client.get(DEF_BASE, headers=ORIGIN_HEADER)
+        assert resp.status_code == 200
+        data = resp.json()
+        assert isinstance(data, dict)
+        assert "items" in data
+        assert "total" in data
+        assert data["total"] == 1
+        assert len(data["items"]) == 1
+        assert data["items"][0]["entity"] == "contact"
+
+    async def test_list_definitions_with_entity_filter(
+        self, client: AsyncClient, db_session
+    ):
+        """List ?entity=contact returns only contact definitions."""
+        await seed_tenant_and_users(db_session)
+        await login_client(client, "admin@tenanta.com")
+        await _create_definition(client)
+        resp = await client.get(
+            f"{DEF_BASE}?entity=contact", headers=ORIGIN_HEADER
+        )
+        assert resp.status_code == 200
+        data = resp.json()
+        assert data["total"] == 1
+        assert all(item["entity"] == "contact" for item in data["items"])
+
+    async def test_list_definitions_invalid_entity_returns_422(
+        self, client: AsyncClient, db_session
+    ):
+        """List with unregistered entity filter returns 422 (consistent with create)."""
+        await seed_tenant_and_users(db_session)
+        await login_client(client, "admin@tenanta.com")
+        resp = await client.get(
+            f"{DEF_BASE}?entity=invalid_entity_xyz", headers=ORIGIN_HEADER
+        )
+        assert resp.status_code == 422
+
+    async def test_list_definitions_without_entity_read_returns_403(
+        self, client: AsyncClient, db_session
+    ):
+        """cf-only user listing contact definitions gets 403 (owner read check)."""
+        seed = await seed_tenant_and_users(db_session)
+        await _create_cf_only_user(db_session, seed)
+        await login_client(client, "cfonly@tenanta.com")
+        resp = await client.get(
+            f"{DEF_BASE}?entity=contact", headers=ORIGIN_HEADER
+        )
+        assert resp.status_code == 403
+
+
+@pytest.mark.asyncio
+class TestCustomFieldDefinitionUpdate:
+    """PATCH /api/v1/custom-fields/definitions/{id}"""
+
+    async def test_update_definition_returns_200(
+        self, client: AsyncClient, db_session
+    ):
+        """Owner can update their own definition."""
+        await seed_tenant_and_users(db_session)
+        await login_client(client, "admin@tenanta.com")
+        def_id = await _create_definition(client)
+        resp = await client.patch(
+            f"{DEF_BASE}/{def_id}",
+            json={"label": "Updated Label"},
+            headers=ORIGIN_HEADER,
+        )
+        assert resp.status_code == 200
+        assert resp.json()["label"] == "Updated Label"
+
+    async def test_update_definition_other_owner_returns_403_not_500(
+        self, client: AsyncClient, db_session
+    ):
+        """Viewer updating admin's definition gets 403, never a 500."""
+        await seed_tenant_and_users(db_session)
+        await login_client(client, "admin@tenanta.com")
+        def_id = await _create_definition(client)
+        await login_client(client, "viewer@tenanta.com")
+        resp = await client.patch(
+            f"{DEF_BASE}/{def_id}",
+            json={"label": "Hacked"},
+            headers=ORIGIN_HEADER,
+        )
+        assert resp.status_code == 403
+
+
+@pytest.mark.asyncio
+class TestCustomFieldDefinitionDelete:
+    """DELETE /api/v1/custom-fields/definitions/{id}"""
+
+    async def test_delete_definition_returns_204(
+        self, client: AsyncClient, db_session
+    ):
+        """Owner can delete their own definition."""
+        await seed_tenant_and_users(db_session)
+        await login_client(client, "admin@tenanta.com")
+        def_id = await _create_definition(client)
+        resp = await client.delete(f"{DEF_BASE}/{def_id}", headers=ORIGIN_HEADER)
+        assert resp.status_code == 204
+
+    async def test_delete_definition_other_owner_returns_403_not_500(
+        self, client: AsyncClient, db_session
+    ):
+        """Viewer deleting admin's definition gets 403, never a 500.
+
+        Today delete_definition is called WITHOUT user_id → ACL check runs
+        with user_id=None → PermissionError → unhandled → 500.
+        """
+        await seed_tenant_and_users(db_session)
+        await login_client(client, "admin@tenanta.com")
+        def_id = await _create_definition(client)
+        await login_client(client, "viewer@tenanta.com")
+        resp = await client.delete(f"{DEF_BASE}/{def_id}", headers=ORIGIN_HEADER)
+        assert resp.status_code == 403
+
+
+class TestEntityPermissionDerivation:
+    """Unit tests: get_entity_read_permission + owner-registry cleanup."""
+
+    def test_get_entity_read_permission_plural_core_module(self):
+        """'workflow' derives workflows:read — not the contacts:read fallback."""
+        from app.services.entity_permission_service import (
+            ENTITY_PLUGIN_OWNERS,
+            get_entity_read_permission,
+        )
+
+        saved_owner = ENTITY_PLUGIN_OWNERS.pop("workflow", None)
+        try:
+            assert get_entity_read_permission("workflow") == "workflows:read"
+        finally:
+            if saved_owner is not None:
+                ENTITY_PLUGIN_OWNERS["workflow"] = saved_owner
+
+    def test_get_entity_read_permission_singular_core_module(self):
+        """'address' derives addresses:read (module is plural in registry)."""
+        from app.services.entity_permission_service import (
+            ENTITY_PLUGIN_OWNERS,
+            get_entity_read_permission,
+        )
+
+        saved_owner = ENTITY_PLUGIN_OWNERS.pop("address", None)
+        try:
+            assert get_entity_read_permission("address") == "addresses:read"
+        finally:
+            if saved_owner is not None:
+                ENTITY_PLUGIN_OWNERS["address"] = saved_owner
+
+    def test_unregister_entity_model_clears_owner_mapping(self):
+        """unregister_entity_model must clean ENTITY_PLUGIN_OWNERS too."""
+        from app.models.workflow import Workflow
+        from app.services.entity_permission_service import (
+            ENTITY_MODELS,
+            ENTITY_PLUGIN_OWNERS,
+            get_entity_read_permission,
+            register_entity_model,
+            unregister_entity_model,
+        )
+
+        register_entity_model("zzz_unit_test", Workflow, plugin_name="zzz_plugin")
+        assert ENTITY_PLUGIN_OWNERS["zzz_unit_test"] == "zzz_plugin"
+        assert get_entity_read_permission("zzz_unit_test") == "zzz_plugin:read"
+        unregister_entity_model("zzz_unit_test")
+        assert "zzz_unit_test" not in ENTITY_PLUGIN_OWNERS
+        assert "zzz_unit_test" not in ENTITY_MODELS