refactor: Remove redundant standalone Dockerfile.playwright

The standalone Dockerfile is no longer needed since we integrated Playwright
directly into docker-compose.yml using the official Playwright image.

Benefits of removal:
- Simpler setup (no build step required)
- Less maintenance (one less file to keep updated)
- docker-compose.yml approach is more integrated and easier to use

The docker-compose service provides the same functionality with:
- Same base image (mcr.microsoft.com/playwright:v1.49.1-noble)
- Same non-root user execution
- Better integration with existing services

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Dockerfile.playwright

@@ -1,30 +0,0 @@
-# Dockerfile for Playwright testing environment
-# Based on official Playwright Docker image with non-root user setup
-
-FROM mcr.microsoft.com/playwright:v1.49.1-noble
-
-# Create a non-root user for running tests
-RUN useradd -ms /bin/bash pwuser && \
-    mkdir -p /home/pwuser/app && \
-    chown -R pwuser:pwuser /home/pwuser
-
-# Switch to non-root user
-USER pwuser
-
-# Set working directory
-WORKDIR /home/pwuser/app
-
-# Copy package files
-COPY --chown=pwuser:pwuser package.json pnpm-lock.yaml ./
-
-# Install pnpm globally for the user
-RUN npm install -g pnpm
-
-# Install dependencies
-RUN pnpm install --frozen-lockfile
-
-# Copy the rest of the application
-COPY --chown=pwuser:pwuser . .
-
-# Run Playwright tests
-CMD ["pnpm", "exec", "playwright", "test"]