Sub-ticket of PLUTO-441 PWA install-completeness: close iOS/standalone gaps so Pluto installs cleanly on iPhone(Safari A2HS), Android/Chrome, Mac(Safari Add-to-Dock + Chrome), Windows/Linux Chrome/Edge. layout.tsx metadata: add appleWebApp{capable,title:Pluto,statusBarStyle:default} + repoint icons.apple to existing public/apple-touch-icon-180x180.png (currently the maskable icon-192 = cropped on iOS) + optional mobile-web-app-capable; verify SW (/sw.js) registration+scope. Additive/reversible, no schema/auth/email. Firefox desktop = no PWA install (Mozilla removed), documented not chased. · pluto