feat(opencode): Add cost of the models in the model picker

[ak127a]

Issue for this PR

Closes #14524

Type of change

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

What does this PR do?

This PR adds the cost of the model in the model selector on web/desktop and TUI

How did you verify your code works?

I built the app locally and tested that desktop, web and TUI version are now showing the cost.

Screenshots / recordings

Web UI

TUI

Desktop app

Checklist

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

[github-actions]

Hey! Your PR title feat(model selector): Add cost of the models on the right side 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. 👍