feat: add Docker support with single-port deployment

Add complete Docker configuration for containerized deployment:
- Multi-stage Dockerfile using official Bun runtime
- docker-compose.yml for single-port stack orchestration
- Host-mounted database volume with auto-initialization
- Custom database init script using bun:sqlite
- Entrypoint script for seamless database setup
- Environment configuration template
- Comprehensive DOCKER.md documentation

Key features:
- Single exposed port (3001) serving both API and frontend
- Database persists in ./data directory on host
- Auto-creates database from template on first startup
- Health checks for monitoring
- Architecture-agnostic (works on x86 and ARM64)

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

docker-entrypoint.sh

@@ -0,0 +1,62 @@
+#!/bin/sh
+set -e
+
+# Docker container entrypoint script
+# Handles database initialization on first startup
+
+echo "=========================================="
+echo "Quickawards - Docker Entrypoint"
+echo "=========================================="
+
+# Database location in volume mount
+DB_PATH="/data/award.db"
+TEMPLATE_DB="/app/award.db.template"
+APP_DB_PATH="/app/src/backend/award.db"
+
+# Check if database exists in the volume
+if [ ! -f "$DB_PATH" ]; then
+  echo ""
+  echo "📦 Database not found in volume mount."
+  echo "   Initializing from template database..."
+  echo ""
+
+  # Copy the template database (created during build with drizzle-kit push)
+  cp "$TEMPLATE_DB" "$DB_PATH"
+
+  # Ensure proper permissions
+  chmod 644 "$DB_PATH"
+
+  echo "✅ Database initialized at: $DB_PATH"
+  echo "   This database will persist in the Docker volume."
+else
+  echo ""
+  echo "✅ Existing database found at: $DB_PATH"
+  echo "   Using existing database from volume mount."
+fi
+
+# Create symlink from app's expected db location to volume mount
+# The app expects the database at src/backend/award.db
+# We create a symlink so it points to the volume-mounted database
+if [ -L "$APP_DB_PATH" ]; then
+  # Symlink already exists, remove it to refresh
+  rm "$APP_DB_PATH"
+elif [ -e "$APP_DB_PATH" ]; then
+  # File or directory exists (shouldn't happen in production, but handle it)
+  echo "⚠ Warning: Found existing database at $APP_DB_PATH, removing..."
+  rm -f "$APP_DB_PATH"
+fi
+
+# Create symlink to the volume-mounted database
+ln -s "$DB_PATH" "$APP_DB_PATH"
+echo "✅ Created symlink: $APP_DB_PATH -> $DB_PATH"
+
+echo ""
+echo "=========================================="
+echo "Starting Quickawards application..."
+echo "Port: ${PORT:-3001}"
+echo "Environment: ${NODE_ENV:-production}"
+echo "=========================================="
+echo ""
+
+# Execute the main command (passed as CMD in Dockerfile)
+exec "$@"