Implement Playwright-based X scraper with AI-powered newsletter generation

Major changes:
- Replace Nitter RSS with Playwright browser automation for direct X scraping
- Scrape all 37 configured tech accounts in parallel
- Add OpenRouter AI integration for topic-based summaries (xiaomi/mimo-v2-flash:free model)
- Update prompts for factual, emotion-free analysis with post links
- Add console output for newsletter preview in dry-run mode
- Update Dockerfile to Playwright v1.57.0 with necessary browser dependencies
- Implement WRAP workflow method for AI-assisted development guidance

Technical improvements:
- Fixed TypeScript compilation (unused parameter in XScraper)
- Newsletter pipeline successfully processes 37 accounts -> AI summaries -> HTML email
- Full end-to-end test validated: scraping, processing, AI generation, email template

Pipeline flow:
1. Scrape X profiles with Playwright (parallel, configurable timeout)
2. Filter tweets by time window and content type
3. Categorize into AI/ML, Software Engineering, Tech & Startups
4. Generate AI summaries for each topic
5. Create cross-topic daily insights
6. Render HTML newsletter with highlights and trending topics
7. Send via email (or print to console in dry-run mode)

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

docker/Dockerfile

@@ -1,7 +1,7 @@
 # =============================================================================
 # Build Stage
 # =============================================================================
-FROM node:20-alpine AS builder
+FROM node:20-bookworm AS builder
 
 WORKDIR /app
 
@@ -14,29 +14,23 @@ COPY tsconfig.json ./
 COPY src ./src
 RUN npm run build
 
-# Prune dev dependencies
-RUN npm prune --production
-
 # =============================================================================
-# Production Stage
+# Production Stage - Using Playwright base image
 # =============================================================================
-FROM node:20-alpine AS production
-
-# Security: run as non-root user
-RUN addgroup -g 1001 -S nodejs && \
-    adduser -S newsletter -u 1001
+FROM mcr.microsoft.com/playwright:v1.57.0-noble AS production
 
 WORKDIR /app
 
-# Copy built application
-COPY --from=builder --chown=newsletter:nodejs /app/node_modules ./node_modules
-COPY --from=builder --chown=newsletter:nodejs /app/dist ./dist
-COPY --from=builder --chown=newsletter:nodejs /app/package.json ./
-
-USER newsletter
+# Copy built application and dependencies
+COPY --from=builder /app/node_modules ./node_modules
+COPY --from=builder /app/dist ./dist
+COPY --from=builder /app/package.json ./
 
 # Set timezone (can be overridden via env)
 ENV TZ=Europe/Warsaw
 
+# Run as non-root user (pwuser is Playwright's default user)
+USER pwuser
+
 # Default command
 CMD ["node", "dist/index.js"]