fix(codex): honor CLI yolo/model and stabilize approval request ids

[cjb0001]

Summary

Fixes Codex permission/model override handling to prevent iOS approval loops in sessions launched with explicit CLI modes (notably --permission-mode yolo / safe-yolo).

Problem

Mobile metadata updates could overwrite CLI-intended mode/model defaults during message handling, causing repeated approvals and unstable permission behavior.

Changes

• Preserve CLI-provided permission-mode and model as authoritative defaults.
• Ignore incoming fallback/default/null metadata that would unintentionally clobber explicit CLI overrides.
• Stabilize permission request ID handling and message override resolution.
• Add focused tests for override behavior and Codex MCP client stability.

Files changed

• packages/happy-cli/src/codex/messageOverrides.ts
• packages/happy-cli/src/codex/codexMcpClient.ts
• packages/happy-cli/src/codex/runCodex.ts
• packages/happy-cli/src/index.ts
• packages/happy-cli/src/codex/__tests__/messageOverrides.test.ts
• packages/happy-cli/src/codex/__tests__/codexMcpClient.test.ts

Notes

This PR is stacked on top of fix/codex-resume-passthrough to keep review diff focused.