chore: bump better-auth

Bumps the npm_and_yarn group with 1 update in the /docs directory: [better-auth](https://github.com/better-auth/better-auth/tree/HEAD/packages/better-auth).


Updates `better-auth` from 1.4.22 to 1.6.2
- [Release notes](https://github.com/better-auth/better-auth/releases)
- [Changelog](https://github.com/better-auth/better-auth/blob/main/packages/better-auth/CHANGELOG.md)
- [Commits](https://github.com/better-auth/better-auth/commits/better-auth@1.6.2/packages/better-auth)

---
updated-dependencies:
- dependency-name: better-auth
  dependency-version: 1.6.2
  dependency-type: direct:production
  dependency-group: npm_and_yarn
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

docs/package.json

@@ -71,7 +71,7 @@
     "@vercel/analytics": "^1.6.1",
     "@y-sweet/react": "^0.6.3",
     "ai": "^6.0.5",
-    "better-auth": "~1.4.15",
+    "better-auth": "~1.6.2",
     "better-sqlite3": "^12.6.2",
     "class-variance-authority": "^0.7.1",
     "framer-motion": "^12.26.2",