Add Codex model options (codex)

[numnx]

🧩 Task: Add Codex model options

Automated task PR opened by Code UX for T01.

📋 Summary

Sprint: Sprint 153 · Settings Page Docs, New Codex Models, CLI Config File · Task: T01

Implement settings documentation/help affordances for every settings subcategory, add the new Codex model IDs, support per-provider Docker config file mode selection, and fix Tasks page project selection so navbar and in-page selectors do not fight each other.

📝 Full Task Prompt

## Objective
Add `gpt-5.6-sol`, `gpt-5.6-terra`, and `gpt-5.6-luna` as selectable Codex models without changing existing defaults or provider routing behavior.

## Scope
- `src/repositories/settings-defaults.ts`
- `tests/backend/repositories/settings-repository.test.ts`
- `tests/backend/domain/settings/settings-sanitizers/ai-provider-sanitizer.test.ts`
- `tests/dashboard/lib/settings-view-models.test.ts`
- `docs/settings/provider-routing.md`
- `docs-web/user/providers-and-models.md`

## Implementation Requirements
1. Add the three new model IDs to the `CODEX_MODELS` array in `src/repositories/settings-defaults.ts`, keeping `gpt-5.5` as the default Codex model.
2. Update focused backend and dashboard tests that assert Codex model catalog/default behavior so the new IDs are included and existing defaults still pass.
3. Update provider/model documentation to mention the new Codex models as selectable options while preserving the existing routing and model override semantics.

## Constraints
- Do not change `DEFAULT_VIRTUAL_WORKER_MODELS.codex` or the default provider setting model unless a failing test proves the repo already expects that.
- Do not remove or reorder existing model IDs in a way that changes default UI selection behavior.
- Do not add external dependencies or runtime network model discovery.

## Verification
- `pnpm run test:backend -- tests/backend/repositories/settings-repository.test.ts tests/backend/domain/settings/settings-sanitizers/ai-provider-sanitizer.test.ts`
- `pnpm run test:dashboard -- tests/dashboard/lib/settings-view-models.test.ts`
- `pnpm run lint`
- Success means the new Codex IDs are accepted by settings/model option helpers and no existing Codex defaults changed.

✅ QA Review

⏳ QA review runs after this PR is opened. Check the task card in the dashboard for the outcome once it lands.

🤖 Model & Provider

Provider	Codex CLI
Model	gpt-5.5

⏱️ Timing

Started	2026-07-07 01:58:31 UTC
Finished	2026-07-07 02:02:26 UTC
Duration	3m 55s

📊 Token Usage

Metric	Value
Input tokens	121,236
Cached input tokens	553,728
Output tokens	5,193
Total tokens	680,157
Invocations	1
Tool calls	28
Active time	3m 18s

Included usage estimate (subscription/local login): $1.04

🌿 Branch Info

Base: feature/CODUX-153-settings-page-docs-new-codex-models-cli-config-file
Head: task/feature-codux-153-settings-page-docs-new-codex-m-t01-codex-mra02jun

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🤖 Generated by Code UX