Extends apply_model_template() to substitute model-specific facts from
runtime lookups instead of hardcoded V4 claims:
- {context_window_note}: resolved from context_window_for_model();
if unknown, emits fallback wording instead of guessing
- {subagent_economics}: resolved from input_cost_note() (new public
pricing helper); cost-agnostic fallback when pricing is unknown
- {model_thinking_note}: gated on model_supports_reasoning();
empty string when the model does not emit thinking tokens
The hardcoded "1M-token window", "$0.14/M Flash", and V4 thinking
strategy will only reach models whose capability lookups return those
values (DeepSeek V4 family). Non-DeepSeek models get accurate facts
or honest "unknown" wording.
Adds input_cost_note() to pricing.rs — returns a one-line sub-agent
cost description, or None when pricing is unavailable.
Hunter Bown
29edb6d0cf