v1.3.1

Added

• Subagents can now request a model by capability tier instead of a concrete id: model: tier:fast, tier:normal, or tier:strong in an agent definition. The tier resolves to a curated model within the parent's current provider, so it works regardless of which single provider you are authed to. On a miss it falls back to the provider's curated normal, then to the parent model with a warning (never your default model).
• Added a subagentModel setting: the default model (tier keyword or concrete id) for spawned subagents whose definition pins no model.