confluence-mdx: emitter가 width 있는 ac:image에 ac:custom-width 속성을 추가합니다 (#947)

## Summary

- emitter의 `_figure_attrs_to_ac_image`, `_emit_figure` 두 경로에서 `ac:width`
설정 시 `ac:custom-width="true"` 속성을 함께 추가합니다
- FC(`converter/core.py`)는 `ac:custom-width="true"`가 있어야 `ac:width`를 MDX
`width=`로 변환합니다 — 이 속성이 없으면 roundtrip 시 width가 손실됩니다

## Test plan

- [x] `pytest tests/test_mdx_to_storage/test_emitter.py` — 54/54 pass
- [x] `pytest tests/ --ignore=tests/test_unused_attachments.py` —
871/871 pass
- [x] `make test-reverse-sync` — 42/42 pass

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Co-authored-by: Atlas <atlas@jk.agent>

Author: 3 people

confluence-mdx/bin/mdx_to_storage/emitter.py

@@ -257,6 +257,7 @@ def _figure_attrs_to_ac_image(img_attrs_str: str) -> str:
     filename = os.path.basename(src) if src else ""
     ac_attrs = ['ac:align="center"']
     if width:
+        ac_attrs.append('ac:custom-width="true"')
         ac_attrs.append(f'ac:width="{width}"')
 
     return (
@@ -339,6 +340,7 @@ def _emit_figure(block: Block, link_resolver: Optional[LinkResolver] = None) ->
 
     attrs = ['ac:align="center"']
     if width:
+        attrs.append('ac:custom-width="true"')
         attrs.append(f'ac:width="{width}"')
 
     parts = [f"<ac:image {' '.join(attrs)}>"]

confluence-mdx/tests/test_forward_converter_image_width.py

@@ -0,0 +1,39 @@
+from converter.core import ConfluenceToMarkdown
+from mdx_to_storage import emit_document, parse_mdx
+
+
+def _roundtrip_mdx_via_storage_xhtml(mdx: str, tmp_path) -> str:
+    xhtml = emit_document(parse_mdx(mdx))
+    converter = ConfluenceToMarkdown(xhtml)
+    converter.load_attachments(
+        input_dir=str(tmp_path),
+        output_dir="/images",
+        public_dir=str(tmp_path),
+        skip_image_copy=True,
+    )
+    return converter.as_markdown()
+
+
+def test_figure_width_survives_storage_roundtrip(tmp_path):
+    mdx = """<figure>
+  <img src="/images/path/sample.png" alt="Sample" width="700">
+</figure>
+"""
+
+    markdown = _roundtrip_mdx_via_storage_xhtml(mdx, tmp_path)
+
+    assert 'width="700"' in markdown
+    assert 'src="/images/sample.png"' in markdown
+
+
+def test_list_item_figure_width_survives_storage_roundtrip(tmp_path):
+    mdx = """1. Text <br/>
+  <figure data-layout="center" data-align="center">
+  <img src="/images/path/sample-image.png" alt="sample-image.png" width="712" />
+  </figure>
+"""
+
+    markdown = _roundtrip_mdx_via_storage_xhtml(mdx, tmp_path)
+
+    assert 'width="712"' in markdown
+    assert 'src="/images/sample-image.png"' in markdown

confluence-mdx/tests/test_mdx_to_storage/test_emitter.py

@@ -242,7 +242,7 @@ def test_emit_figure_to_ac_image_with_width():
     xhtml = emit_document(parse_mdx(mdx))
     assert (
         xhtml
-        == '<ac:image ac:align="center" ac:width="700"><ri:attachment ri:filename="sample.png"></ri:attachment></ac:image>'
+        == '<ac:image ac:align="center" ac:custom-width="true" ac:width="700"><ri:attachment ri:filename="sample.png"></ri:attachment></ac:image>'
     )
 
 
@@ -299,7 +299,7 @@ def test_emit_figure_in_mixed_document():
     xhtml = emit_document(parse_mdx(mdx))
     assert "<h1>Overview</h1>" in xhtml
     assert "<p>Some text.</p>" in xhtml
-    assert '<ac:image ac:align="center" ac:width="600">' in xhtml
+    assert '<ac:image ac:align="center" ac:custom-width="true" ac:width="600">' in xhtml
     assert '<ri:attachment ri:filename="diagram.png">' in xhtml
     assert "<ac:caption><p>Architecture diagram</p></ac:caption>" in xhtml
     assert "<p>More text after image.</p>" in xhtml
@@ -552,7 +552,7 @@ def test_emit_list_item_with_figure_becomes_ac_image_sibling():
     # <p> should contain only the text (no figure, no trailing br)
     assert '<li><p>텍스트</p>' in xhtml
     # ac:image should be a sibling of <p>
-    assert '<ac:image ac:align="center" ac:width="712">' in xhtml
+    assert '<ac:image ac:align="center" ac:custom-width="true" ac:width="712">' in xhtml
     assert '<ri:attachment ri:filename="sample-image.png"></ri:attachment>' in xhtml
     # empty <p /> after the image
     assert '<p />' in xhtml