typing: make albums_in_dir, sorted_walk and other utils generic over AnyStr

[snejus]

Fixes #6808

• This change makes the path-handling utilities is_hidden, sorted_walk, unique_path, remux_mpeglayer3_wav and albums_in_dir work with both str and bytes paths instead of assuming bytes everywhere.

• Architecturally, the PR moves these helpers toward a single generic path flow using AnyStr, so callers can stay in their native path type while the utilities preserve that type through traversal, filtering, and hidden-file checks.

• In albums_in_dir, the multi-disc detection logic was updated to support both string and byte paths by splitting regex handling into str and bytes variants while keeping the existing album-collapsing behavior the same.

• High-level impact: this reduces path-conversion friction, improves typing consistency across importer and util code, and makes the filesystem helpers easier to reuse as the codebase continues moving away from bytes-only assumptions.

[github-actions]

Thank you for the PR! The changelog has not been updated, so here is a friendly reminder to check if you need to add an entry.

[codecov]

Codecov Report

❌ Patch coverage is 84.61538% with 8 lines in your changes missing coverage. Please review.
✅ Project coverage is 74.84%. Comparing base (8ddae79) to head (db2e2fc).
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
beets/util/extension.py	70.00%	1 Missing and 2 partials ⚠️
beets/importer/tasks.py	89.47%	1 Missing and 1 partial ⚠️
beets/util/__init__.py	87.50%	1 Missing and 1 partial ⚠️
beets/util/hidden.py	83.33%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #6806      +/-   ##
==========================================
- Coverage   74.85%   74.84%   -0.01%     
==========================================
  Files         163      163              
  Lines       20970    20986      +16     
  Branches     3300     3304       +4     
==========================================
+ Hits        15697    15707      +10     
- Misses       4519     4522       +3     
- Partials      754      757       +3     

Files with missing lines	Coverage Δ
beetsplug/fetchart.py	74.18% <100.00%> (ø)
beets/util/hidden.py	54.16% <83.33%> (+6.54%)	⬆️
beets/importer/tasks.py	90.87% <89.47%> (-0.29%)	⬇️
beets/util/__init__.py	80.35% <87.50%> (-0.33%)	⬇️
beets/util/extension.py	76.47% <70.00%> (-4.18%)	⬇️

... and 1 file with indirect coverage changes

🚀 New features to boost your workflow:

• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[Copilot]

Pull request overview

PR make path helper move from “bytes-only brain” toward “AnyStr brain” so code can walk filesystem with str or bytes and keep same type through.

Changes:

• Make beets.util.hidden.is_hidden accept PathLike and decode/normalize into Path.
• Change beets.util.sorted_walk typing/output to be generic over AnyStr (str/bytes) and adjust sorting to match path type.
• Update importer albums_in_dir multi-disc detection so regex + ignore patterns work for both str and bytes paths.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
beets/util/hidden.py	Widen hidden-path helper to accept broader path inputs and normalize via Path.
beets/util/init.py	Make sorted_walk generic over AnyStr and preserve path type through traversal.
beets/importer/tasks.py	Make albums_in_dir and multi-disc regex logic work for str and bytes paths.