feat(codex): support provider-specific review models

[neverdie0710]

Codex providers can now choose their own review model in the TUI. For example, switching from provider A to B projects A’s or B’s selection into the top-level review_model used by Codex, without requiring separate CODEX_HOME directories.

The optional selection is stored as meta.codexReviewModel and takes precedence over common config. Leaving it empty preserves existing configuration behavior. Preview, normal switching, temporary launches and shared-session launches honor the override; live-config backfill preserves the underlying value so clearing an override restores the previous behavior, including clearing while a temporary launch is still running. Chat/Anthropic model routing also preserves an explicitly selected review model even when it is absent from the model catalog.

Includes English/Chinese UI help and README documentation, plus regression coverage for persistence, common-config precedence, clearing after backfill, official providers without metadata, both launch paths, routing and narrow-terminal rendering.

Validation:

• cargo fmt --check
• Ten review-model unit tests pass.
• All 71 provider_service integration tests and all nine start_codex_shared tests pass.
• Broader Codex library tests: 724 pass, one ignored, one fails in the unchanged transcript-index fixture. The same failure reproduces on clean upstream 8a5614db (codex_refresh_keeps_the_selected_message_when_prepend_moves_its_page: unable to open temporary SQLite index).

cargo clippy --all-targets --locked is blocked by the existing clippy::reversed_empty_ranges error in src/cli/tui/ui/home_chart.rs:806, also with the pinned Rust 1.91.1 toolchain. With only that lint allowed, the all-target Clippy check passes (existing warnings remain). No unrelated lint or transcript-index changes are included.