fix(reply): stabilize draft path for send-email

[ChenMiaoi]

Summary

Describe the intent of this change and the user-visible outcome.

Related Issues

Link issues if applicable.

• Closes [Bug]: reply send fails when storage.data_dir is relative and kernel.tree is set #10
• Related to [Bug]: reply send fails when storage.data_dir is relative and kernel.tree is set #10

What Changed

Testing

List what you ran locally.

Documentation

• No documentation change needed
• README updated
• Config / workflow docs updated
• Other docs updated

Checklist

• The change is focused on one topic
• Commit messages follow the repository convention
• Tests were added or updated when needed
• User-visible behavior was documented when needed
• I checked for regressions in related workflows

Notes For Reviewers

Anything that needs special attention during review.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!

[ChenMiaoi]

@codex review

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. What shall we delve into next?

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".