Function me_handler 

pub async fn me_handler(
    __arg0: State<AppState>,
    __arg1: Authenticated,
) -> Result<Json<UserInfo>, (StatusCode, String)>

Get current user info GET /api/v1/auth/me

Returns identity info for the authenticated caller. Works for:

• JWT-authenticated users (looks up full user record)
• API key authentication (returns identity from claims)
• Dev mode (returns synthetic dev identity from claims)