fix(review): use canonical GPT-5.6 Sol model ID

[rNoz]

Use the Codex catalog's canonical gpt-5.6-sol identifier for GPT-5.6 Sol and migrate persisted gpt-5.6 settings so existing users do not keep sending the stale model ID.

Fixes #1070

Root cause

The review settings catalog exposed GPT-5.6 Sol with the model value gpt-5.6, while OpenAI Codex 0.144.4 publishes the model as gpt-5.6-sol in its authoritative models.json. AgentsTab feeds that catalog value into persisted Codex settings, so both new selections and previously saved review, tour, or guide selections could retain the stale identifier.

Changes

• Change the AgentsTab model catalog entry to gpt-5.6-sol with the display label GPT-5.6 Sol.
• Add migrateCodexSection to migrate stale review, tour, and guide model selections.
• Migrate per-model reasoning-effort and fast-mode preferences from gpt-5.6 to gpt-5.6-sol.
• Preserve an existing canonical preference when both stale and canonical keys are present, remove stale keys, and leave unrelated model settings unchanged.
• Add focused catalog and settings migration coverage.

This does not change provider defaults, reasoning options, fast-mode behavior, or settings for unrelated models.

Validation

• bun test packages/ui/components/AgentsTab.test.ts packages/ui/hooks/useAgentSettings.test.ts: 13 passed, 0 failed, 16 assertions.
• bun run typecheck with TypeScript 5.9.3 available on PATH: passed.
• bun test: 2,132 passed, 99 skipped, 0 failed.
• bun run --cwd apps/review build: passed.
• bun run build:hook: passed after the review build.

Manual testing gap

A live launch against Codex 0.144.4 was not run because the locally installed Codex CLI was older during validation. The canonical identifier was verified against Codex 0.144.4 models.json, and the focused tests cover catalog selection plus persisted migration behavior.

Please, let me know if you want that I do some further E2E test/proof. Otherwise, ready.

[rNoz]

Author of reported bug #1070 (comment) has confirmed this PR fixes the issue.