fix(types): Add TypeScript types to exports for moduleResolution bundler compatibility

[joao-imi]

Description

TypeScript projects using moduleResolution: "bundler" cannot resolve type declarations because the exports field doesn't include types entries.

Changes

• Add types entries to exports field in package.json (must be first in each export object);
• Create types/hooks/index.d.ts with type definitions for HCaptchaProvider and useHCaptcha;
• Fix incorrect file extensions in hooks exports (.jsx → .js to match Babel output);