Renames VITE_AUTH_* to VITE_OIDC_* to match the stack convention.
Adds a dedicated VITE_OIDC_POST_LOGOUT_REDIRECT_URI instead of deriving
it from the redirect URI via string replace. Switches from Dockerfile
ARG/ENV to a committed src/Budget.Client/.env so Vite picks up
production values at build time without needing build-arg overrides.
.env.local is gitignored for localhost dev overrides.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Spencer Twaddle