Add project spending details to Cost tab

[Gnonymous]

Summary

• Make project rows in the Cost tab clickable, with a focused project view and a back action.
• Show the selected range's total, model costs, trend, and exact hourly or daily cost rows.
• Build project breakdowns from the same local records as the existing totals, preserving legacy snapshot decoding.

Verification

• swift run CodingBar --self-test passed, including per-project model and trend reconciliation for Today, 7d, and 30d.
• Rendered the Cost list and project detail in dark English and light Chinese.
• git diff --check passed.

The dollar figures remain standard API price equivalents, not subscription charges.

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-27T16:04:02.916524Z	9018430	PR opened

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" or "@codex security review".

Codex reacts with 👀 while any review is running, comments if it has suggestions, and reacts with 👍 once all reviews finish with no findings.

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 9018430e90

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".

[chatgpt-codex-connector]

Clear project details when the refreshed range drops the project

When the periodic refresh produces an overview where the selected project is no longer present—such as after midnight for the Today range, or when it falls outside the top-eight project cutoff—the lookup fails and ?? selected keeps rendering the old ProjectStat. The detail page therefore continues to label stale totals as the current range indefinitely; clear/close the selection or render a missing-project state instead of falling back to the pre-refresh value.

Useful? React with 👍 / 👎.