switch from tinacms to sanity

Dockerfile

@@ -1,26 +1,14 @@
-# Shared build: generates /dist (Astro site + admin SPA) and tina/__generated__
+# Build: generates /dist (Astro static site + Sanity Studio SPA)
 FROM node:24 AS builder
 WORKDIR /app
 COPY package*.json ./
-RUN npm ci --legacy-peer-deps
+RUN npm ci
 COPY . .
-ENV TINA_PUBLIC_IS_LOCAL=true
-RUN npm run build:docker
+RUN npm run build
 
-# Frontend: Nginx serving the static site + TinaCMS admin SPA
+# Frontend: Nginx serving the static site + Sanity Studio SPA
 FROM nginx:alpine AS frontend
 RUN rm /etc/nginx/conf.d/default.conf
 COPY nginx.conf /etc/nginx/conf.d/default.conf
 COPY --from=builder /app/dist /usr/share/nginx/html
 EXPOSE 80
-
-# Backend: TinaCMS self-hosted API server
-FROM node:24 AS backend
-WORKDIR /app
-COPY package*.json ./
-RUN npm ci --legacy-peer-deps --omit=dev
-COPY backend/ ./backend/
-COPY --from=builder /app/tina/__generated__ ./tina/__generated__
-ENV NODE_ENV=production
-EXPOSE 3000
-CMD ["node", "backend/index.js"]