Grammar corrections now run through a deterministic guard that blocks protected glossary names/aliases from being changed

tests/test_corrections.py

@@ -171,6 +171,56 @@ def test_apply_corrections_requires_unique_match_when_configured():
     assert "more than once" in result.skipped[0].reason
 
 
+def test_apply_corrections_skips_when_guard_rejects_replacement():
+    transcript = parse_transcript_json(
+        """
+        [
+          {"id": 1, "speaker": "Eric", "start": 0.0, "end": 1.0, "text": "Hrank moves."}
+        ]
+        """
+    )
+    correction = CorrectionCandidate(
+        id=1,
+        original_text="Hrank",
+        corrected_text="Frank",
+        confidence=0.8,
+    )
+
+    result = apply_corrections(
+        transcript,
+        [correction],
+        confidence_threshold=0.8,
+        replacement_mode="require_unique",
+        correction_guard=lambda before, after: "protected term changed" if before != after else None,
+    )
+
+    assert result.transcript[0].text == "Hrank moves."
+    assert len(result.skipped) == 1
+    assert result.skipped[0].reason == "protected term changed"
+    assert result.skipped[0].actual_text == "Hrank moves."
+
+
+def test_apply_corrections_without_guard_remains_permissive():
+    transcript = parse_transcript_json(
+        """
+        [
+          {"id": 1, "speaker": "Eric", "start": 0.0, "end": 1.0, "text": "Frank moves."}
+        ]
+        """
+    )
+    correction = CorrectionCandidate(
+        id=1,
+        original_text="Frank",
+        corrected_text="Hrank",
+        confidence=0.8,
+    )
+
+    result = apply_corrections(transcript, [correction], confidence_threshold=0.8)
+
+    assert result.transcript[0].text == "Hrank moves."
+    assert result.skipped == []
+
+
 def test_apply_corrections_skips_empty_original_text():
     transcript = _transcript()
     correction = CorrectionCandidate(