feat: add pull --with-comments sidecar

`mdcx pull --with-comments` fetches inline + page comments via
`/rest/api/content/{id}/child/comment` (paginated, two-level reply
expansion) and writes them to `<output>.comments.json` alongside the
Markdown file. Inline comments correlate to the markdown's
`data-inline-comment="UUID"` spans through their `marker_ref` field.

Comment bodies are stored as raw Confluence storage XML; pushing
comments back is not implemented. Requires `--output`.

chore: rename module to go.bigb.es/confluence-md-utilities

Move CLI to cmd/mdcx/, add justfile and CLAUDE.md

Restructure to standard Go project layout: merge package cmd
into package main under cmd/mdcx/. Fix .gitignore to use /mdcx
so it only ignores the binary at repo root. Update install path
in README.md.

false

Rename module, add features, fix round-trip fidelity

- Rename module to sourcecraft.dev/bigbes/confluence-md-utilities
- Add fmt command with syntax highlighting (--color=auto/force/disabled)
- Add shell completions for all commands with file extension hints
- Preserve ac:layout/ac:layout-section/ac:layout-cell through round-trips
- Preserve ac:macro-id on code blocks and TOC macros
- Preserve table class/style attributes and colgroup column widths
- Preserve TOC macro as <!-- ac:toc --> comment
- Fix table cell rendering to preserve bold, italic, code, br, links
- Fix user references (ri:userkey) and attachment images (ri:attachment)
- Fix inline spacing between formatting elements in list items

false

Initial commit: mdcx — Markdown to Confluence XML converter

Bidirectional converter between Markdown and Confluence storage format XML
with self-hosted Confluence Server/Data Center sync support.

Features:
- convert: Markdown → Confluence XML
- extract: Confluence XML → Markdown
- embed: embed Markdown into Confluence XML template (marker-based)
- pull/push: sync pages with Confluence via REST API + PAT auth
- fmt: pretty-print Confluence XML with sensible indentation
- Round-trip preservation of inline comments, user refs, attachment images

false