fix: allow useLogout without authModalContext

[dphilipson]

useLogout does not depend on UI components and now will no longer throw an error when used outside an AuthModalProvider.`

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PR-Codex overview

The focus of this PR is to refactor the authentication context handling by introducing an optional context hook for better flexibility.

Detailed summary

• Introduces useOptionalAuthContext hook for optional authentication context handling
• Updates useLogout hook to use useOptionalAuthContext instead of useAuthContext

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