docs(claude-md): strengthen testing requirements and add UI test command

[J2TeamNNL]

Summary

• Updates principle [WIP] Fix tab state persistence and query execution timing issues #7 (Testability) to require unit tests for all testable code changes and UI automation for user-flow changes when deterministic
• Adds xcodebuild ... -only-testing:TableProUITests command to the Build & Development Commands section
• Updates mandatory rule Fix data grid undo/redo and multi-row deletion bugs #4 (Tests) with the same stricter wording

These are project-convention changes that affect every future PR.

[github-actions]

Thank you for your contribution! Before we can merge this PR, you need to sign our Contributor License Agreement.

To sign, please comment below with:

I have read the CLA Document and I hereby sign the CLA.

---

I have read the CLA Document and I hereby sign the CLA.

---

1 out of 2 committers have signed the CLA.
✅ (J2TeamNNL)[https://github.com/J2TeamNNL]
❌ @claude
_{You can retrigger this bot by commenting recheck in this Pull Request. Posted by the CLA Assistant Lite bot.}

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 7271232286

ℹ️ About Codex in GitHub

Codex has been enabled to automatically 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 👍.

When you sign up for Codex through ChatGPT, Codex can also answer questions or update the PR, like "@codex address that feedback".

[chatgpt-codex-connector]

Point the UI test command at an existing target

In this repo the new command selects TableProUITests, but I inspected TablePro.xcodeproj/project.pbxproj and TablePro.xcodeproj/xcshareddata/xcschemes/TablePro.xcscheme, and the only test target/testable is TableProTests. Apple documents -only-testing identifiers as being rooted at the test target (test_target/test_type/test_function), so this command cannot run a valid bundle here and will fail for anyone following the added UI-test guidance until a TableProUITests target is added or the command is removed.

Useful? React with 👍 / 👎.