refactor: 从 pnpm 切换到 npm

- 去掉 corepack/pnpm，Docker 构建不再卡在下载 pnpm
- Dockerfile 使用 npm ci + npm prune --omit=dev
- 删除 pnpm-lock.yaml，新增 package-lock.json

Dockerfile

@@ -7,21 +7,15 @@ FROM node:22-slim AS builder
 # China npm mirror
 RUN npm config set registry https://registry.npmmirror.com
 
-# Enable corepack for pnpm
-RUN corepack enable && corepack prepare pnpm@latest --activate
-
 WORKDIR /app
 
-# pnpm also uses npm mirror
-RUN pnpm config set registry https://registry.npmmirror.com
-
 # Copy package manifests first (layer caching for dependency install)
-COPY package.json pnpm-lock.yaml ./
+COPY package.json package-lock.json ./
 
 # Install all dependencies (including devDependencies for building)
-RUN pnpm install --frozen-lockfile
+RUN npm ci
 
-# Install Chromium for rebrowser-playwright (during build, included in image)
+# Install Chromium for rebrowser-playwright
 RUN npx playwright install chromium
 
 # Copy source code
@@ -29,10 +23,10 @@ COPY tsconfig.json tsup.config.ts ./
 COPY src/ src/
 
 # Build the project
-RUN pnpm build
+RUN npm run build
 
 # Remove devDependencies to slim down node_modules for production
-RUN pnpm prune --prod
+RUN npm prune --omit=dev
 
 # =============================================================================
 # Stage 2: Production
@@ -41,7 +35,6 @@ RUN pnpm prune --prod
 FROM node:22-slim
 
 # Install Chromium dependencies required by Playwright/rebrowser-playwright
-# These are the shared libraries Chromium needs to run in headless mode.
 RUN apt-get update && apt-get install -y --no-install-recommends \
     libnss3 \
     libnspr4 \