feat(app): model tooltip metadata in chooser (per Figma request)

[kearns-cu]

Summary

• add model metadata tooltips to Choose Model
• infer source provider names for models based on model id/name
• show Latest/Free status in tooltip titles

Testing

• not run (pre-push hook failed in @opencode-ai/enterprise; likely unrelated)

Screenshots

Now

Before

Fixes #9691
Requested by Adam (Figma: https://www.figma.com/design/nm7fT1he2hcniHIipY1iEk/opencode-open-source?node-id=62-15981&t=FSAXJprvW4rRgLZU-0)

[github-actions]

Hey! Your PR title Desktop: model tooltip metadata in chooser 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]

The following comment was made by an LLM, it may be inaccurate:

No duplicate PRs found

[github-actions]

Thanks for your contribution!

This PR doesn't have a linked issue. All PRs must reference an existing issue.

Please:

1. Open an issue describing the bug/feature (if one doesn't exist)
2. Add Fixes #<number> or Closes #<number> to this PR description

See CONTRIBUTING.md for details.

[kearns-cu]

The nix desktop CI failure on macos-15-intel is unrelated to my changes. The error is from upstream nixpkgs package models-dev-0-unstable-2026-01-14 not supporting x86_64-darwin. This PR only touches UI code.