setup-mstacklisted

# Set up mstack models Write the user's model choices to `~/.config/mstack/models.json`. Keep the file portable so the same role names work in every supported Harness. ## Read the current choices 1. Detect the model names available in the current Harness. 2. Read `~/.config/mstack/models.json` when it exists. 3. When no file exists, start from the seven-role example below. A repository checkout also provides `profiles/models.example.json`. 4. Use `inherit-parent` for the current session model. Native delegation must support inheritance; a new CLI process needs the concrete parent model via `run-role --parent-model <name>`. Use `auto` for the Harness's default model selection, which may differ from the current session. Do not write a model name that the current Harness did not report as available. ## Write the configuration Store a JSON object with a `roles` object and an optional `overrides` object. Use these roles: - `implementer` for feature and refactoring workers. - `reviewer` for review and verification workers. - `judge` for comparisons and final decisions. - `explorer` for read-only repository exploration. - `synthesizer` for combining findings into one answer or artifact. - `candidate` for independent alternatives evaluated by an arena. - `operator` for environment or lifecycle operations. Merge the requested changes into the existing file. Preserve other role choices, Harness overrides, and unrelated fields. Fill missing roles with `inherit-parent