fix: only use the 20 percent if maxTokens is equal to contextWindow or if maxTokens is not provided

Author: daniel-lxs

webview-ui/src/utils/model-utils.ts

@@ -101,7 +101,8 @@ export const calculateTokenDistribution = (
 	// Get the actual max tokens value from the model
 	// If maxTokens is valid, use it, otherwise reserve 20% of the context window as a default
 	const defaultReserved = Math.ceil(safeContextWindow * 0.2)
-	const reservedForOutput = maxTokens && maxTokens > 0 && maxTokens < defaultReserved ? maxTokens : defaultReserved
+	const reservedForOutput =
+		maxTokens && maxTokens > 0 && maxTokens === safeContextWindow ? defaultReserved : (maxTokens ?? defaultReserved)
 
 	// Calculate sizes directly without buffer display
 	const availableSize = Math.max(0, safeContextWindow - safeContextTokens - reservedForOutput)