- Add optional scope parameter to startAuthorization function signature
- Include scope in authorization URL query parameters when provided
- Update auth function to pass through scope from provider.clientMetadata
- Add tests to verify scope is correctly included/excluded from auth URL

This enhancement allows clients to specify authorization scopes during the OAuth flow.

Previously, this check was `value instanceof ZodType`, which breaks if
the user is using a different version of Zod than the library. Instead,
do the check using the structure of the input object rather than its
prototype chain.

Additionally, this adds a vendored version of Zod to use for tests, which
ensures that regressions like this would be caught next time.

feat: Add scope parameter to startAuthorization function

- simpler test for empty object
- only test public zod properties (parse, safeParse)

Confirmed that vendored-library tests still pass. Note that you need the --testPathIgnorePatterns to avoid the __tests__ directory (this is what was breaking the build):
$ npm test -- --testPathIgnorePatterns="vendor"

Fix Zod object detection logic

Release 1.11.2 - update version