Add draw.io diagram export as PNG

[splieth]

Export draw.io diagrams embedded in Confluence pages as PNG images alongside the Markdown files. Diagrams are automatically downloaded from page attachments and referenced as inline images in the output.

[Copilot]

Pull request overview

Adds support for exporting draw.io diagrams embedded in Confluence pages by downloading the corresponding PNG attachments and converting draw.io macros into inline image references in the generated Markdown.

Changes:

• Introduce attachment fetching/downloading in the Confluence client layer.
• Add draw.io macro detection + replacement in the renderer and thread the Confluence client through export APIs.
• Add renderer tests for draw.io handling and bump package metadata/versioning.

Reviewed changes

Copilot reviewed 5 out of 6 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
uv.lock	Bumps locked package version to 0.2.0.
src/confluence2md/renderer.py	Replaces draw.io macros with image tags and downloads PNG attachments during export.
src/confluence2md/client.py	Adds Attachment model plus fetch_attachments and download_attachment helpers.
src/confluence2md/cli.py	Passes Confluence client through to export functions so diagrams can be processed.
tests/test_renderer.py	Adds unit tests covering draw.io macro parsing, PNG selection, and export behavior.
pyproject.toml	Adds readme metadata and updates version to 0.2.0.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[splieth]

@copilot apply changes based on the comments in this thread

[Copilot]

@copilot apply changes based on the comments in this thread

All review feedback has been applied in commit 1932010 (local), but the push is blocked because PR #1 was already merged and feature/drawio is now a protected ref. These improvements would need to go into a new PR on top of main.

Here's a summary of every change made:

src/confluence2md/renderer.py

• _find_drawio_png: now filters by media_type == "image/png" and does case-insensitive title matching, so a non-PNG attachment with a .png name is correctly skipped.
• export_page: creates a per-page assets subdirectory (output_dir/{page_slug}/) so diagram attachments from different pages never overwrite each other.
• _process_drawio_macros: (a) renamed html param to body to avoid shadowing the stdlib html module; (b) downloads each attachment only once per page using a downloaded: dict[str, str] cache keyed by attachment ID; (c) uses html.escape() on both the src and alt attribute values to prevent HTML injection from user-controlled Confluence content; (d) uses Path(title).name to strip directory separators from filenames before building the relative src path.

src/confluence2md/client.py

• download_attachment: uses Path(attachment.title).name to strip any ../ path-traversal components before writing to disk.

tests/test_client.py

• Added test_fetch_attachments, test_fetch_attachments_empty, test_fetch_attachments_multiple — cover response parsing including _links.download and metadata.mediaType.
• Added test_download_attachment, test_download_attachment_creates_directory, test_download_attachment_prevents_path_traversal — verify correct file path, directory creation, and that ../evil/file.png writes only inside the destination directory.

tests/test_renderer.py

• Updated test_process_drawio_macros to pass a real Path and assert the per-page subdirectory prefix in the src.
• Updated test_export_page_with_drawio to assert ![Architecture](Diagrams/Architecture.png) (reflecting the subdirectory).
• Added test_find_drawio_png_wrong_media_type_skipped — non-image/png attachment with matching name is ignored.
• Added test_find_drawio_png_case_insensitive — ARCHITECTURE.PNG matches diagram name Architecture.
• Added test_process_drawio_macros_deduplicates_downloads — same diagram referenced twice triggers only one download call.

All 54 tests pass and CodeQL reports no alerts.