why

• to give users a stable contract for getting the extension archive, instead of reaching into the internals of stagehand & relying on brittle file paths that may change across releases

what changed

added an extension archive getter in all three SDKs:

• TypeScript: await getExtensionArchive() → Uint8Array
• Python: get_extension_archive() → bytes
• Go: ExtensionArchive() → []byte

test plan

• added tests covering archive contents, extraction, repeatability, and independent buffer

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Summary by cubic

Adds a public getter for the bundled Stagehand extension archive across all three SDKs, so users no longer need to reach into internal file paths.

• TypeScript: getExtensionArchive() returns a Uint8Array; Python: get_extension_archive() returns bytes; Go: ExtensionArchive() returns []byte.
• Tests verify the archive is a valid ZIP, extractable, repeatable, and that mutating a returned copy doesn't corrupt later calls.