Support `opusplan`

[konard]

That should be supported as both --model opusplan and --plan-model opus with --model sonnet.

From docs: https://code.claude.com/docs/en/model-config

opusplan Special mode that uses opus during plan mode, then switches to sonnet for execution

If we can support also for example --plan-model sonnet with --model haiku, that would be even better, investigate the possibility.

Please collect data related about the issue to this repository, make sure we compile that data to ./docs/case-studies/issue-{id} folder, and use it to do deep case study analysis (also make sure to search online for additional facts and data), and propose possible solutions (including known existing components/libraries, that solve similar problem or can help in solutions).

[konard]

See full log: https://gist.githubusercontent.com/konard/052ae6094a32e9e58e4aa8389766020b/raw/9388a1acc1e6517836ff49aa91c0a36506e9c431/solution-draft-log-pr-1774738604493.txt

Did opusplan actually worked? Why the plan was not displayed and we got straight to sonnet model execution?

We need to download all logs and data related about the issue to this repository, make sure we compile that data to ./docs/case-studies/issue-{id} folder, and use it to do deep case study analysis (also make sure to search online for additional facts and data), in which we will reconstruct timeline/sequence of events, find root causes of the problem, and propose possible solutions (including known existing components/libraries, that solve similar problem or can help in solutions).

If there is not enough data to find actual root cause, add debug output and verbose mode if not present, that will allow us to find root cause on next iteration.

If issue related to any other repository/project, where we can report issues on GitHub, please do so. Each issue must contain reproducible examples, workarounds and suggestions for fix the issue in code.