v0.8.6

Fixes

• Ordered lists starting at 0 now round-trip. A list authored with order=0 — schema-valid (the minimum is 0) and editable in Confluence — was treated as falsy and re-rendered as starting at 1, dropping the attribute; it is now preserved in both block and table-cell contexts.

• Block marks on bodiedExtension and bodiedSyncBlock are no longer dropped on ADF→Markdown, matching their extension / syncBlock siblings. This was a confirmed loss for a full-width bodiedSyncBlock, which encodes its width as a breakout mark (the node carries no layout attr) — that width silently disappeared on the round-trip and now survives.

Internal (no public-API or behavior changes)

• Single-source the MD-params key names for block-level marks so the encode (block_marks_params) and decode (parse_block_marks) sides can't silently drift, and fold the duplicated media-border encode loop into one helper.
• Share the colspan×rowspan grid-footprint calculation between Table.iter_cells and the parser's dense→sparse step, so both agree on grid geometry from one definition.
• Extract shared helpers for marker-prefixed blocks (list / task items) and the block-marks <data> prefix; drop a dead parameter from _render_children.

Full changes: v0.8.5...v0.8.6