fix(agent): pass correct model config to small provider builder (#2236)

0xarcher created 

When building the small model provider, we were incorrectly passing
largeModelCfg instead of smallModelCfg to buildProvider. This caused
isAnthropicThinking to check the wrong model config, preventing the
small model from enabling Anthropic thinking mode even when configured.

Fixes #2141

Change summary

internal/agent/coordinator.go | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

Detailed changes

internal/agent/coordinator.go 🔗 

@@ -508,7 +508,7 @@ func (c *coordinator) buildAgentModels(ctx context.Context, isSubAgent bool) (Mo
 		return Model{}, Model{}, errors.New("large model provider not configured")
 	}
 
-	smallProvider, err := c.buildProvider(smallProviderCfg, largeModelCfg, true)
+	smallProvider, err := c.buildProvider(smallProviderCfg, smallModelCfg, true)
 	if err != nil {
 		return Model{}, Model{}, err
 	}