fix(i-d): RBAC-Comprehensive 4 Failures behoben — http_exception_handler um dict-detail-Durchreichung erweitert (strukturierte Error-Codes AGENTS.md-konform, body[detail] = raw_detail dict statt stringify); 3 Contact-Payload-Feldnamen korrigiert (firstname/surname statt first_name/last_name in legacy-editor Tests); test_rbac_comprehensive 102/102 gruen

app/main.py

@@ -22,7 +22,7 @@ logger = logging.getLogger(__name__)
 
 from app.config import get_settings  # noqa: E402
 from app.core.db import close_engine, get_engine  # noqa: E402
-from app.core.error_codes import ApiError, build_error_response  # noqa: E402
+from app.core.error_codes import ERROR_CODES, ApiError, build_error_response  # noqa: E402
 from app.core.middleware import (  # noqa: E402
     AuditMiddleware,
     CSRFMiddleware,
@@ -519,11 +519,26 @@ def create_app() -> FastAPI:
             504: "service_timeout",
         }
         code = status_to_code.get(exc.status_code, "internal_error" if exc.status_code >= 500 else "validation_error")
-        body = build_error_response(
-            code=code,
-            detail=str(exc.detail) if exc.detail else None,
-            trace_id=trace_id,
-        )
+        # Structured detail passthrough (AGENTS.md): when a route raises
+        # HTTPException with a dict detail containing a machine-readable ``code``,
+        # preserve the structured shape instead of stringifying it.
+        raw_detail = exc.detail
+        if isinstance(raw_detail, dict):
+            inner_code = raw_detail.get("code", code)
+            body = build_error_response(
+                code=inner_code if inner_code in ERROR_CODES else code,
+                detail=raw_detail.get("detail") or str(raw_detail),
+                trace_id=trace_id,
+            )
+            # Preserve the full structured detail as a nested object so clients
+            # can read ``resp.json()["detail"]["code"]``.
+            body["detail"] = raw_detail
+        else:
+            body = build_error_response(
+                code=code,
+                detail=str(exc.detail) if exc.detail else None,
+                trace_id=trace_id,
+            )
         resp = JSONResponse(status_code=exc.status_code, content=body)
         if trace_id:
             resp.headers["X-Trace-Id"] = trace_id