create-agent skill documents per-agent model/thinking config that the runtime silently discards

[Zazzles2908]

The bundled create-agent skill (assets/skills/create-agent/SKILL.md) tells agents to set per-agent model: <provider>/<model> and a thinking: block in agents/<name>/config.yaml ("Add when: The default model is wrong for this role"). In the current runtime this mechanism does not exist:

• @mavis/local-runtime/dist/agent/sqlite-store.js normalizeConfig() keeps only defaultWorkspaceDir from the agent's config file — model and thinking keys are read and silently dropped (no warning logged).
• Resolved model comes exclusively from the session's effectiveModel (UI model picker, set via api/routes/agents.ts) or the global root config.yaml defaultModel; children inherit the session model (local-task-runner.ts).
• Additionally, thinking.effort on custom-provider model entries is not honored: model-resolver.js reads configuredEffort only on the builtin provider.* tree; the BYOK path (model-resolver-byok.js) passes none, so the emitted thinking level is the mode-derived default.

Counter-example that works: per-session model selection via the UI picker, and thinking_config.mode on model entries (verified: switchable toggle emits thinking:{type:enabled/disabled} for DeepSeek via openai-completions.js).

Ask: either implement per-agent model:/thinking: in agent config files (and wire configuredEffort for BYOK custom providers), or correct the create-agent skill docs to point at the session-picker mechanism. Silent dropping of documented config is the dangerous part.

Evidence: config.yaml agent entries containing only defaultWorkspaceDir (verified on 13 agents); runtime source quoted above; version MiniMax Code desktop v3.0.57.