fix: Fix Dockerfile build context and ensure normalizeAssetUrl is used everywhere

- Fix Dockerfile to use correct paths (context is already apps/web)
- Ensure normalizeAssetUrl is used when setting preview URLs after upload
- This ensures all asset URLs go through the proxy

apps/web/Dockerfile

@@ -6,8 +6,8 @@ FROM node:20-alpine AS deps
 RUN apk add --no-cache libc6-compat
 WORKDIR /app
 
-# Copy only apps/web package files
-COPY apps/web/package.json apps/web/package-lock.json* ./
+# Copy only package files (context is already apps/web)
+COPY package.json package-lock.json* ./
 RUN npm ci --legacy-peer-deps
 
 # Stage 2: Builder