Core: Avoid bootstrapping text metadata for manual translations (#369)

src/co_op_translator/core/project/translation_manager.py

@@ -1407,13 +1407,10 @@ class TranslationManager:
                         else None
                     )
                     if not legacy_hash:
-                        save_text_metadata_for_source(
-                            lang_dir,
-                            original_file,
-                            lang_code,
-                            root_dir=self.root_dir,
-                        )
-                        migrated += 1
+                        # If there is no legacy inline metadata, do not synthesize
+                        # a fresh metadata record from the current source hash.
+                        # Doing so would incorrectly mark unknown/manual translations
+                        # as up-to-date and skip retranslation.
                         continue
 
                     extra_fields = {"original_hash": legacy_hash}

tests/co_op_translator/core/project/test_translation_manager.py

@@ -245,6 +245,32 @@ def test_is_translation_outdated_walks_up_to_lang_dir(tmp_path):
     assert "lesson-1/README.md" in data
 
 
+def test_migrate_legacy_inline_text_metadata_skips_files_without_legacy_block(tmp_path):
+    root_dir = tmp_path
+    translations_dir = root_dir / "translations"
+    lang_dir = translations_dir / "ko"
+
+    source_file = root_dir / "guide.md"
+    source_file.write_text("# Source\n", encoding="utf-8")
+
+    translated_file = lang_dir / "guide.md"
+    translated_file.parent.mkdir(parents=True, exist_ok=True)
+    translated_file.write_text("# Manual translated content\n", encoding="utf-8")
+
+    manager = MagicMock()
+    manager.root_dir = root_dir
+    manager.translations_dir = translations_dir
+    manager.language_codes = ["ko"]
+    manager._migrate_legacy_inline_text_metadata = (
+        TranslationManager._migrate_legacy_inline_text_metadata.__get__(manager)
+    )
+
+    migrated = manager._migrate_legacy_inline_text_metadata()
+
+    assert migrated == 0
+    assert not (lang_dir / ".co-op-translator.json").exists()
+
+
 @pytest.mark.asyncio
 async def test_retranslate_outdated_files(mock_translation_manager, temp_project_dir):
     """Tests retranslation of outdated files."""