docs: add guardLatestUserMessage to TypeScript Bedrock guardrails

src/content/docs/user-guide/concepts/model-providers/amazon-bedrock.mdx

@@ -511,6 +511,10 @@ When a guardrail is triggered:
 - Output redaction (disabled by default): If a guardrail policy is triggered, the output is redacted
 - Custom redaction messages can be specified for both input and output redactions
 
+:::note[Latest Message Evaluation]
+When `guardLatestUserMessage: true`, only the most recent user message is sent to guardrails for evaluation instead of the entire conversation. This can improve performance and reduce costs in multi-turn conversations where earlier messages have already been validated.
+:::
+
 </Tab>
 </Tabs>
 

src/content/docs/user-guide/concepts/model-providers/amazon-bedrock.ts

@@ -409,6 +409,7 @@ async function guardrailsExample() {
         output: false, // Default: false
         outputMessage: '[Assistant output redacted.]', // Custom redaction message
       },
+      guardLatestUserMessage: true, // Only evaluate the latest user message (default: false)
     },
   })