feat(codex): add WebSocket settings UI - #1965

Related GitHub Issue

Closes #1963 after all prerequisite PRs are merged.

Dependencies and merge order

Depends on provider activation #1967, which in turn requires transport #1964 and reasoning-history fix #1966.

#1966 and #1964 can merge independently → #1967 → this PR (#1965). Update this branch from the main branch after activation merges. Keep this PR as a draft until then so users never receive a checkbox that has no runtime effect.

Standalone type/build checks can fail before the prerequisites merge because the new shared provider setting and default are not yet present on the base branch.

Description

The webview-only portion of the original #1964: 28 files, all under webview-ui.

• Add the per-profile Use WebSocket checkbox for OpenAI Codex authenticated through a ChatGPT subscription.
• Keep edits buffered in Settings until the user clicks Save; default to off using the shared backend default.
• Add provider-control and unsaved-Settings regression coverage.
• Include translations for all 18 supported locales.
• Preserve the Story Gallery fixture, Playwright type shim, and light/dark visual baselines for both checkbox states.

There are no backend, shared-package, or lockfile changes here. The webview subtree is byte-for-byte identical to the original unsplit PR. Combining #1966, #1964, #1967, and this PR reproduces the complete original Git tree exactly, including binary visual baselines.

Test Procedure

Validation rerun against the combined backend + UI state:

• 18 tests passed across OpenAICodex.spec.tsx and SettingsView.unsaved-changes.spec.tsx.
• Webview type check passed.
• Focused ESLint checks passed during the initial UI split with no suppression-count increases; UI code has not changed during the subsequent backend split.

The original light/dark Playwright baselines are preserved unchanged and were not regenerated during either split. Standalone CI is not claimed until the prerequisites are merged and this branch is updated.

Manual verification after all parts are applied:

1. Sign in to OpenAI Codex with a ChatGPT subscription.
2. Enable Use WebSocket and verify that changing it does not immediately save Settings.
3. Click Save, reopen Settings, and switch/import/export provider profiles; confirm the saved checkbox value survives.
4. Verify requests use WebSocket when enabled. Disable the checkbox and Save to return to HTTP streaming.

Local validation used Node 24.7.0 / pnpm 10.8.1; the repository requests Node 22.23.1.

Pre-Submission Checklist

• Scope: Webview changes only; backend responsibilities are reviewed separately.
• Self-Review: Scope and exact preservation verified.
• Testing: Focused regression tests and type check passed with prerequisites present.
• Visual Snapshot: Story Gallery coverage and light/dark baselines retained unchanged.
• Documentation Impact: Provider documentation should describe the opt-in checkbox when the full feature is released; documentation files remain outside these PRs.

No changeset or changelog entry is included. The original unsplit state is preserved on a backup branch in the source fork.