Add comprehensive Docker test environment for installation validation

Add complete Docker testing infrastructure to validate all 3 installation methods

Features:
- Dockerfile: Ubuntu 22.04 with Node.js 20, Python 3, prerequisites
- docker-compose.yml: Orchestrate 3 test containers + verification
- Test suite with 5 scripts:
  * common.sh: Shared utilities and verification functions
  * test-interactive-install.sh: Test Option 2 (interactive installer)
  * test-master-prompt-install.sh: Test Option 1 (master prompt)
  * test-manual-install.sh: Test Option 3 (manual installation)
  * verify-all-installations.sh: Master verification with report generation
- run-tests.sh: Quick start script for easy test execution

What Gets Tested:
✓ Prerequisites (Node.js, npm, Python, Git, jq)
✓ Claude Code installation and version
✓ Settings files (settings.json, settings.local.json)
✓ 38 agents across 8 departments
✓ MCP tools (@z_ai/mcp-server, @z_ai/coding-helper, llm-tldr)
✓ UI/UX Pro Max skill
✓ Ralph CLI (optional, can be enabled)

Test Results:
- Saved to docker/test-env/test-results/
- Detailed logs for each test method
- Component verification counts
- Comprehensive final report with pass/fail status

Usage:
cd docker/test-env
./run-tests.sh

Or manually:
docker-compose up verify-all

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

docker/test-env/Dockerfile

@@ -0,0 +1,62 @@
+# Dockerfile for Testing Claude Code Suite Installation
+# Tests all 3 installation methods: Interactive, Master Prompt, and Manual
+
+FROM ubuntu:22.04
+
+# Prevent interactive prompts during build
+ENV DEBIAN_FRONTEND=noninteractive
+ENV NODE_VERSION=20
+ENV PYTHON_VERSION=3.11
+
+# Install system prerequisites
+RUN apt-get update && apt-get install -y \
+    curl \
+    wget \
+    git \
+    build-essential \
+    python3 \
+    python3-pip \
+    nodejs \
+    npm \
+    jq \
+    vim \
+    bash \
+    && rm -rf /var/lib/apt/lists/*
+
+# Upgrade Node.js to version 20
+RUN npm install -g n && \
+    n $NODE_VERSION && \
+    npm install -g npm@latest
+
+# Install Claude Code globally
+RUN npm install -g @anthropic-ai/claude-code
+
+# Create test user
+RUN useradd -m -s /bin/bash testuser && \
+    usermod -aG sudo testuser
+
+# Set up working directory
+WORKDIR /home/testuser
+RUN chown -R testuser:testuser /home/testuser
+
+# Switch to test user
+USER testuser
+
+# Set environment variables
+ENV HOME=/home/testuser
+ENV PATH="$HOME/.local/bin:$PATH"
+
+# Create Claude directory structure
+RUN mkdir -p ~/.claude/{agents,plugins,hooks,sessions,projects}
+
+# Copy test suite files
+COPY --chown=testuser:testuser test-suite/ $HOME/test-suite/
+
+# Make scripts executable
+RUN chmod +x $HOME/test-suite/*.sh
+
+# Set working directory for tests
+WORKDIR /home/testuser/test-suite
+
+# Default command
+CMD ["/bin/bash"]