okhp3-google-gis-client-auth

OverKill Hill P³ client-only Google Identity Services (GIS) auth workflow. Use when designing, implementing, or troubleshooting client-only Google Identity Services (GIS) OAuth token flows for React or TypeScript SPAs on static hosts. Use for Google Sign-In, Calendar or Tasks read access, popup token acquisition, session-scoped token storage, expiry handling, silent re-authentication, GCP OAuth setup, or porting this pattern without a backend, Client Secret, redirect URI, or refresh token. Keep provider-specific write APIs outside this skill.