GHSA-CMWH-G2H8-C222 Poweradmin: OIDC `sub` collation bypass in Poweradmin leading to account takeover

Preface Poweradmin maps OIDC identities into local users through oidcuserlinks.oidcsubject plus providerid. In the MySQL schema, the OIDC link table explicitly uses utf8mb4unicodeci, which is case-insensitive and accent-insensitive. OIDC sub is a stable external subject identifier and should be...