gpt-5.3 codex review: Phase 4

tests/test_errors.py

@@ -4,6 +4,8 @@ import pytest
 
 from transcription.errors import AppError
 from transcription.errors import ErrorCategory
+from transcription.errors import build_error_envelope
+from transcription.errors import canonical_error_category
 from transcription.errors import classify_unexpected_error
 from transcription.errors import new_error_id
 
@@ -44,3 +46,14 @@ class TestAppErrorHelpers:
         assert "boom" in err.message
         assert err.suggestion
         assert err.error_id
+
+    def test_envelope_categories_use_canonical_contract_values(self):
+        """API/UI envelope categories are normalized to canonical short identifiers."""
+        validation = AppError("x", category=ErrorCategory.USER_INPUT)
+        timeout = AppError("x", category=ErrorCategory.INFRA_TRANSIENT)
+        internal = AppError("x", category=ErrorCategory.INTERNAL_UNEXPECTED)
+
+        assert canonical_error_category(validation) == "validation"
+        assert canonical_error_category(timeout) == "timeout"
+        assert canonical_error_category(internal) == "internal"
+        assert build_error_envelope(validation).category == "validation"