feat:Add enterprise foundry support parameters

[ak4153]

Issue for this PR

Closes #

Type of change

• Bug fix
• New feature
• Refactor / code improvement
• Documentation

What does this PR do?

This adds support for extra runtime provider options on type: "api" auth entries in ~/.local/share/opencode/auth.json.

Before this change, API auth only accepted a key. That made it hard to use providers behind enterprise gateways or proxies that also need per-user connection settings such as baseURL, custom headers, timeout overrides, or mTLS client certificate paths.

With this PR, those values can be stored under auth.json in an options object and are merged into the provider runtime options before the SDK client is created. TLS file paths are loaded and forwarded into the fetch layer so mTLS-backed endpoints work without requiring global certificate environment setup.

I also updated the docs to show the intended split:

• opencode.json defines a custom provider ID and model list
• auth.json stores credentials and per-user connection overrides

This was motivated by Azure Foundry / enterprise proxy use cases, but the implementation is generic and applies to any API-backed provider.

How did you verify your code works?

I ran:

• cd packages/opencode && bun test --timeout 30000 test/auth/auth.test.ts test/provider/provider.test.ts
• cd packages/opencode && bun run typecheck
• cd packages/app && bun run typecheck

The added tests cover auth round-trip for API auth with options, runtime merge of auth-side options, and TLS material loading into fetch.

Screenshots / recordings

No UI change.

Checklist

• I have tested my changes locally
• I have not included unrelated changes in this PR

[github-actions]

Hey! Your PR title Add antrophic foundry doesn't follow conventional commit format.

Please update it to start with one of:

• feat: or feat(scope): new feature
• fix: or fix(scope): bug fix
• docs: or docs(scope): documentation changes
• chore: or chore(scope): maintenance tasks
• refactor: or refactor(scope): code refactoring
• test: or test(scope): adding or updating tests

Where scope is the package name (e.g., app, desktop, opencode).

See CONTRIBUTING.md for details.

[github-actions]

Thanks for updating your PR! It now meets our contributing guidelines. 👍

[github-actions]

Thanks for updating your PR! It now meets our contributing guidelines. 👍