chore: sync model pricing from OpenRouter API

providers/moonshot.toml

@@ -14,8 +14,8 @@ display_name = "Kimi K2.6"
 tier = "frontier"
 context_window = 262144
 max_output_tokens = 16384
-input_cost_per_m = 0.7448
-output_cost_per_m = 4.655
+input_cost_per_m = 0.75
+output_cost_per_m = 3.5
 supports_tools = true
 supports_vision = true
 supports_streaming = true