docs: clarify stealth init script visibility

[mturac]

Summary

• clarify how init_script interacts with Patchright's isolated execution context in Stealthy mode
• point page_action users to page.evaluate(..., isolated_context=False) when they need to read globals placed on window
• keep the existing runtime behavior unchanged

Refs #350

Tests

• git diff --check origin/main...HEAD

[yetval]

Thanks for this. I think this is patchright working as intended rather than a bug, since the init script does run, it just sits in the isolated world so your evaluate calls can't see it. Anyone who needs it in the main world can already pass isolated_context=False. My honest take is this doesn't really need a code change and a short docs note would cover it, but happy to be wrong.

[mturac]

Good point, thanks for the context. I replaced the runtime change with a docs-only note that keeps the existing behavior intact and points page_action users to page.evaluate(..., isolated_context=False) when they need to read globals from the page main world.