Allow project-specific configuration for approval policies

What feature would you like to see?

Based on https://github.com/openai/codex/issues/8714

Codex does not currently support per-project settings (for approval policies or otherwise) in its config.toml file. Currently, the approval_policy is applied globally across all projects, which limits flexibility when different projects require different levels of review or security standards.

Proposed Change:

I propose updating the configuration logic to allow approval_policy (and potentially other settings) to be defined on a per-project basis within config.toml. This will enable users to override the global policy for specific repositories or directories.

I am planning to implement this change and will submit a Pull Request (PR) shortly to address this If possible and get thumbs up