docs: comprehensive auto-generated documentation for Codex codebase

[tangent-sh]

Auto-generated Comprehensive Documentation

hi
This PR adds detailed, structured, and practically useful documentation for the entire Codex codebase in .tangent/ as MDX files. Each file documents core modules, TUI components, configuration, approval logic, utility code, testing approaches, and step-by-step usage patterns/workflows.

Included Docs

• overview.mdx: Repository structure, features, install, getting started.
• codex-cli.mdx: CLI frontend, configuration, security model, usage.
• codex-rs.mdx: Rust backend, crates, business logic, config, sandboxing.
• codex-cli-components.mdx: TUI React/Ink overlays and chat UI.
• codex-cli-core.mdx: Core app and approval business logic (app.tsx, approvals.ts).
• codex-cli-hooks.mdx: Reusable React/Ink hooks (useConfirmation, useTerminalSize).
• codex-cli-utils.mdx: CLI utilities, model/providers registry, file/terminal helpers.
• codex-cli-testing.mdx: Testing strategies, sample tests, and coverage advice.
• usage-examples.mdx: Real-world usage, workflows, advanced scenarios, prompting tips.

All documentation is cross-linked and organized for developer onboarding, contributor development, power-user adoption, and CI integration.

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Ready for review and feedback!

[github-actions]

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I have read the CLA Document and I hereby sign the CLA

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[PramaYudhistira]

thanks for the assist my g, you are so cracked 😭😭