Support Codex lifecycle hooks across rendering and u-haul import

[tom-bywild]

tl,dr

Add full Codex lifecycle hook support to the harness, including shared capability mapping, provider rendering, legacy import, and docs updates.

Task & Solution

• Introduced a shared hook-capabilities module so Codex, Claude, Copilot, and Cursor use one capability matrix for event names and matcher support.
• Extended canonical hooks and Codex rendering to support Codex lifecycle events, features.hooks, and statusMessage.
• Updated u-haul to import both inline .codex/config.toml hooks and standalone .codex/hooks.json, while normalizing deprecated Codex feature flags.
• Refreshed docs and the harness-hook skill to describe the new Codex lifecycle behavior and provider projection rules.

Reasoning

• Shared capability data keeps rendering and import logic aligned and reduces drift.
• The implementation stays provider-specific at the output layer, so the shared module remains small and reusable.
• Tests cover the canonical parser, provider projection, Codex rendering, and blackbox migration flows to keep the change realistic and regression-resistant.

Qualtiy Gates

• pnpm check:write
• pnpm typecheck
• pnpm test
• pnpm test:e2e:containers

Inspiration

"Simplicity is the soul of efficiency." — Austin Freeman