Migrate from Next.js to SvelteKit

- Replace Next.js app with SvelteKit + adapter-node
- basePath /bodenfeuchte configured in svelte.config.js
- MQTT listener starts via hooks.server.ts on server boot
- Chart.js replaces Recharts for the moisture graph
- Dockerfile simplified: single build step, node build output
- Removed custom server.ts (no longer needed)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Dockerfile

@@ -1,27 +1,22 @@
-FROM node:20-alpine AS deps
-WORKDIR /app
-COPY package*.json ./
-RUN npm ci --omit=dev
-
 FROM node:20-alpine AS builder
 WORKDIR /app
+RUN apk add --no-cache python3 make g++
 COPY package*.json ./
 RUN npm ci
 COPY . .
 RUN npm run build
-RUN npx tsc --project tsconfig.server.json
 
 FROM node:20-alpine AS runner
 WORKDIR /app
 ENV NODE_ENV=production
 
-COPY --from=deps /app/node_modules ./node_modules
-COPY --from=builder /app/.next ./.next
-COPY --from=builder /app/dist ./dist
-COPY --from=builder /app/public ./public
+RUN apk add --no-cache python3 make g++
 COPY package*.json ./
+RUN npm ci --omit=dev
+COPY --from=builder /app/build ./build
 
 RUN mkdir -p data
 
 EXPOSE 3000
-CMD ["node", "dist/server.js"]
+ENV PORT=3000
+CMD ["node", "build"]