chore: update Dockerfile for pnpm, modify package.json dependencies, and implement rate limiting

- Switched from npm to pnpm for dependency management in Dockerfile, improving build efficiency.
- Updated Vue and Vue Router versions in package.json for better compatibility.
- Changed placeholder URLs in site.ts to actual Fiverr links and adjusted review count.
- Removed obsolete sitemap.xml file to streamline the project.
- Added a new rate limiting plugin to manage API request limits for the contact endpoint.

Dockerfile

@@ -1,17 +1,29 @@
 # Stage 1: Build
 FROM node:22-alpine AS builder
 WORKDIR /app
-COPY package*.json ./
-RUN npm ci
+
+# Install pnpm via corepack
+RUN corepack enable && corepack prepare pnpm@latest --activate
+
+# Copy manifests first for layer caching
+COPY package.json pnpm-lock.yaml ./
+
+# Install all dependencies (including devDeps needed for build)
+RUN pnpm install --frozen-lockfile
+
+# Copy source and build
 COPY . .
-RUN npm run build
+RUN pnpm build
 
 # Stage 2: Runtime
 FROM node:22-alpine AS runner
+WORKDIR /app
 ENV NODE_ENV=production
 ENV HOST=0.0.0.0
 ENV PORT=3000
-WORKDIR /app
+
+# Nuxt SSR bundles all server deps into .output/server/
 COPY --from=builder /app/.output /app/.output
+
 EXPOSE 3000
 CMD ["node", "/app/.output/server/index.mjs"]