MUST be used when starting a new Flows custom app, especially after Fusion Custom apps Start building (prompt ends with ---Start Building---) or `npx @cognite/cli@latest apps skills pull`. Owns what the short Fusion prompt leaves out: local HTTPS (apps setup-https), GET token/inspect and appHostingAcl WRITE, the models/datamodels fallback, SME story, App-Brief after the conversation, deploy, sign as builder, and submit. Hands Industrial MCP connection to connect-atlas-mcp. Use whenever the user mentions token/inspect, appHostingAcl, mkcert, apps setup-https, SME story, or a clickable https://localhost prototype.