Enhancement: Expand --paths directory arguments to nav-listed files

[virtualguard101]

Summary

Passing a directory to --paths (e.g. docs/obsidian/音视频) is treated as a single path key obsidian/音视频, which is not a nav file entry. Sync skips with:

WARNING changed file not in nav, skip: obsidian/音视频
INFO nothing to sync

Users expect directory paths to mean all nav-listed markdown under that directory.

Steps to reproduce

mkdocs-note ns --paths docs/obsidian/音视频

Nav contains obsidian/音视频/乐理基础.md but not the directory path itself.

Proposed solution

When --paths resolves to a directory:

1. Expand to all nav-listed .md / .ipynb files whose file_rel is under that directory prefix.
2. If the directory has changes but no nav-listed children, log clearly (e.g. no nav-listed files under obsidian/音视频).
3. Optionally support glob patterns (docs/obsidian/音视频/**/*.md).

Acceptance criteria

• --paths docs/obsidian/音视频 syncs all nav-listed files under that tree.
• Passing a single file path still works as today.
• Dry-run lists expanded file set.
• Docs updated with directory vs file semantics.

Related

• Incremental sync and collect_targets in sync.py