feat: show sizes in Miller columns

[MaterAnime]

Summary

• add an optional Size field to the Miller-column view using the existing column settings
• show regular-file sizes immediately and calculate directory sizes asynchronously
• cancel obsolete directory-size work during navigation and sorting
• preserve symlink identity by displaying link instead of a misleading byte count
• avoid size metadata reads for path completion, hidden Size fields, and hidden Miller views

Includes the responsiveness fix from #118 by @nerdislb so folder navigation does not wait for obsolete directory-size work.

Validation

• cargo test --locked: 609 passed
• bash tests/js.sh: 3,101 checks passed
• ./tools/flea-file-budget: passed
• git diff --check: passed
• release package built successfully with makepkg

tests/protocol.sh passes the relevant size, cancellation, list, sort, and quit checks. Its three unrelated thumbnail checks still fail because /tmp/flea-sandbox/flea-media-btrfs/photo_0.jpg is absent. flea-qmllint-gate also retains the existing unused-import, property-override, and incompatible-type baseline findings.

Review notes

The Size field can be disabled from the existing column settings. When disabled, neighbouring-column peeks do not stat files merely to calculate hidden values.

[coderabbitai]

Important

Draft PR not reviewed

Draft PRs are not automatically reviewed by default.

• Trigger a manual review

To automatically review draft PRs, update your CodeRabbit configuration:

reviews:
  auto_review:
    drafts: true

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}