feat: ShellMate - SSH Chess TUI

Play chess in your terminal over SSH. No installs, no accounts.

Features:
- Beautiful terminal-filling chess board with ANSI colors
- Play against Stockfish AI (multiple difficulty levels)
- Two-step move interaction with visual feedback
- Leaderboard with PostgreSQL persistence
- SSH key persistence across restarts

Infrastructure:
- Docker containerized deployment
- CI/CD pipeline for dev/staging/production
- Health checks with auto-rollback
- Landing page at shellmate.sh

Tech: Python 3.12+, asyncssh, python-chess, Stockfish

.github/workflows/ci.yml

@@ -0,0 +1,62 @@
+name: CI
+
+on:
+  push:
+    branches: [main, develop]
+  pull_request:
+    branches: [main, develop]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    
+    steps:
+      - uses: actions/checkout@v4
+      
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+      
+      - name: Install system dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y stockfish
+      
+      - name: Install Python dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install -e ".[dev]"
+      
+      - name: Run linter
+        run: |
+          ruff check src/ tests/
+      
+      - name: Run type checker
+        run: |
+          mypy src/ --ignore-missing-imports
+        continue-on-error: true
+      
+      - name: Run tests
+        run: |
+          pytest tests/ -v --tb=short
+      
+  build:
+    runs-on: ubuntu-latest
+    needs: test
+    
+    steps:
+      - uses: actions/checkout@v4
+      
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+      
+      - name: Build Docker image
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          push: false
+          tags: shellmate:test
+          platforms: linux/amd64,linux/arm64
+          cache-from: type=gha
+          cache-to: type=gha,mode=max