fix(06-03): update test import to use new package structure

- Remove sys.path manipulation from test file
- Use standard package import from kb_workflow.metadata
- Test file now follows the same import pattern as production code

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/test_zhihu_metadata/test_markdown_converter.py

@@ -1,4 +1,4 @@
-"""Tests for MarkdownConverter in kb_zhihu_metadata
+"""Tests for MarkdownConverter in kb_workflow.metadata
 
 Tests cover:
 - Normal image conversion
@@ -8,15 +8,8 @@ Tests cover:
 """
 
 import pytest
-import sys
-from pathlib import Path
 
-# Add kb_zhihu_metadata to path
-zhihu_metadata_path = Path(__file__).parent.parent.parent / "kb-zhihu-metadata"
-if str(zhihu_metadata_path) not in sys.path:
-    sys.path.insert(0, str(zhihu_metadata_path))
-
-from markdown_converter import MarkdownConverter
+from kb_workflow.metadata.markdown_converter import MarkdownConverter
 
 
 class TestMarkdownConverterImages: