revokeAllTokens
Revokes all available token types (access token, refresh token, device secret).
Revocations are performed concurrently. If any individual revocation fails, the others still proceed and all failures are collected.
Return
Result.success with Unit if all revocations succeed, or Result.failure with:
RevokeAllException containing a map of RevokeTokenType to Exception for each token type that failed. Callers can inspect the map to handle partial failures.