Tighten marketplace root removal

[xli-oai]

Summary

• preserve filesystem existence-check errors when removing an installed marketplace root
• remove directory roots with remove_dir_all and regular file roots with remove_file
• return a clear error when the root exists but is neither a file nor a directory

Why

A corrupted marketplace install can leave CODEX_HOME/.tmp/marketplaces/<name> as a regular file. The remove flow should clean that file up instead of treating the path as directory-only and stopping before the removal outcome is complete.

Validation

• just fmt
• cargo test -p codex-core-plugins marketplace_remove
• cargo test -p codex-core-plugins
• cargo test -p codex-cli --test marketplace_remove
• cargo test -p codex-app-server marketplace_remove -- --nocapture
• cargo clippy -p codex-core-plugins --all-targets -- -D warnings

After rebasing onto current main, reran:

• cargo test -p codex-core-plugins marketplace_remove

[xli-oai]

@codex review

[chatgpt-codex-connector]

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Reviewed commit: a5ca8015c7

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[xli-oai]

@codex review

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 910e5dd685

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".