First increment of the approved Phase P RFC (webui-mission). Adds a Vite + React
Router SPA scaffold coexisting with the Next app: index.html with the theme
anti-flash script, src/main.tsx entry, the v1 parity route table under Guest/Auth
guard shells, and a dev proxy (/api, /socket.io ws) to the gateway on 14242 so the
SPA is same-origin in dev. vitest bumped to v3 (vite 8 pairing); existing specs
pass unchanged. Next remains the served app until the P5 cutover.
Co-Authored-By: Claude Fable 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01ESFAnh2t9HmLwng8oW95St