refactor(ui): add shelf menu remove-all option

[alexhb1]

Description

Small refinement to the shelf membership menu in the browser work. Adds "Remove from your shelves" to the menu options, meant to un-assign a book or bulk selection from the user's scoped shelves.

Linked Issue

N/A - Part of #2031

Changes

• Adds "Remove from your shelf" item to the shelf assignment menu
• Updated specs

Manual Testing Steps

N/A

Screenshots (Optional)

Additional Context (Optional)

This is only the component UI. The actual shelf wiring is part of the shelf membership command and wired up by its future users (the book context menu and the bulk action bar).

AI Disclosure

N/A

Checklist

• This PR links and implements an accepted issue.
• This PR is a single focused change.
• There are new or updated tests validating this change.
• I ran just ui check and just api check.
• I have added screenshots if there were any UI changes.
• I have disclosed any AI usage as per the organization AI Policy above.
• I understand all of my submitted changes.

[coderabbitai]

Important

Review skipped

Auto reviews are disabled on base/target branches other than the default branch.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: Repository YAML (base), Organization UI (inherited)

Review profile: ASSERTIVE

Plan: Pro Plus

Run ID: 75a9e9b7-a562-4a7f-9018-61c3da20fe4f

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

---

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.}