[hoyyeva]

Issue for this PR

Fixes #56218

Related: #48163, ollama/ollama#19310.

Type of change

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

What does this PR do?

Restore root --model / -m and pass it to the TUI. For new sessions, a valid explicit model wins over the agent default. For example, opencode --standalone --model ollama/selected starts with that model even when Build specifies ollama/default.

Later manual selections and resumed-session models retain their precedence. Agent configuration and activation are preserved. Malformed model references warn without interrupting session navigation or redirecting a startup prompt into a new session.

How did you verify your code works?

• 62 focused TUI tests and 5 CLI parser tests passed; CLI and TUI typechecks passed.
• Four isolated source CLI/TUI startup cases verified built-in/custom agent overrides, disabled-agent preservation and unchanged saved configuration, using synthetic providers with no real inference.
• The latest review rerun passed 30 focused tests and both package typechecks. Its lifecycle fixtures were blocked at sandbox listener binding. Full repository lint passed; the broader typecheck stopped on missing unrelated console/web dependencies.

Screenshots / recordings

No layout changes.

Checklist

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

[opencode-agent]

Thanks for putting this together, @hoyyeva!

The v2 branch was promoted to dev on 2026-10-10, and dev is now where v2 work happens. This pull request targets a branch that is no longer used, so it's being closed automatically.

Please open it again against dev. You can reuse the same branch: just open a new pull request with dev as the base.