Update browser and PWA app icons

Summary

Replaced the Pennywise favicon, Apple touch icon, standard PWA icons, and Android maskable icon with assets generated from the new logo. Updated the favicon and Vite PWA references, and verified the production frontend build and generated manifest.

Decisions

• Kept the existing PWA icon filenames so the manifest structure did not need to change
• Used a PNG favicon because the supplied source logo is a raster image

Learnings

• Existing installed PWAs may retain a cached home-screen icon until the app is reinstalled or site data is cleared