feat(ui): redesign workbench to Codex-style two-pane layout with status filtering

[AllenReder]

Overview

• Completely refactors the GitHub Workbench UI to a Codex-style two-pane layout (Issue/PR list on the left, full metadata/markdown detail pane on the right).
• Adds on-demand lifecycle status filtering (open as default, merged, and closed) with fast query performance and cache partitioning.
• Adds an adjustable 30%–70% draggable divider defaulting to an equal 1:1 split on wide layouts.
• Adds a floating shadowed filter popover anchored strictly below the search/filter controls.
• Replaces filter glyph with a square funnel icon, moves top-level refresh action to the right of the filter tabs, and moves external GitHub link to the detail header.
• Fully updates server intake queries, shared resource schemas, and bilingual translations.

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[AllenReder]

@codex review

[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 2026-09-02T14:14:39.531936Z	37e4668	Manual request

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[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 37e4668dc1

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".