chore: remove debug console.log statements from production code

Three debug logs left in production paths:

- useAgent.ts: logs task string on every agent execution
- HeroSection.tsx: logs getPageInstructions url/hint on every page visit
- HeroSection.tsx: logs the full execute() result to the console

None of these are error-level events and they leak internal details
to the browser console in production builds.

packages/extension/src/agent/useAgent.ts

@@ -108,7 +108,6 @@ export function useAgent(): UseAgentResult {
 
 	const execute = useCallback(async (task: string) => {
 		const agent = agentRef.current
-		console.log('🚀 [useAgent] start executing task:', task)
 		if (!agent) throw new Error('Agent not initialized')
 
 		setCurrentTask(task)