Add current date and page url to agent context (#1102)

# why
To improve context

# what changed
Added current page and url to the system prompt

# test plan

Author: miguelg719

.changeset/upset-ghosts-shout.md

@@ -0,0 +1,5 @@
+---
+"@browserbasehq/stagehand": patch
+---
+
+Add current page and date context to agent

lib/handlers/stagehandAgentHandler.ts

@@ -237,7 +237,8 @@ STRATEGY:
 - Prefer ariaTree to understand the page before acting; use screenshot for quick confirmation.
 - Keep actions atomic and verify outcomes before proceeding.
 
-For each action, provide clear reasoning about why you're taking that step.`;
+For each action, provide clear reasoning about why you're taking that step.
+Today's date is ${new Date().toLocaleDateString()}. You're currently on the website: ${this.stagehand.page.url}.`;
   }
 
   private createTools() {