Show raw streaming and buffered curl in browser routing example

[rgarcia]

Summary

• Demonstrate both kernel.browsers.fetch (streaming, returns Response) and kernel.browsers.curl (buffered JSON envelope) in the browser-routing example
• Add comments noting when to use each
• Mirrors the equivalent change to the Python SDK

Test plan

• Verified end-to-end with a real API key: prints "status 200" and the full body

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Note

Low Risk
Low risk example-only change; it updates sample usage of kernel.browsers.fetch/curl without affecting SDK behavior or production code paths.

Overview
Updates the examples/browser-routing.ts sample to demonstrate two browser request modes: kernel.browsers.fetch returning a streaming Response (logged via response.text()), and kernel.browsers.curl returning a buffered JSON envelope (logged via buffered.body).

Adds brief guidance comments on when to use each approach and removes the prior status-only logging.

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