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>

src/backend/scripts/init-db.js

@@ -0,0 +1,33 @@
+#!/usr/bin/env bun
+/**
+ * Database initialization script
+ * Creates the database schema using Drizzle ORM
+ */
+
+import Database from 'bun:sqlite';
+import { drizzle } from 'drizzle-orm/bun-sqlite';
+import { migrate } from 'drizzle-orm/bun-sqlite/migrator';
+import * as schema from '../db/schema/index.js';
+import { join } from 'path';
+
+const dbPath = join(process.cwd(), 'src/backend/award.db');
+
+console.log('Creating database at:', dbPath);
+
+// Create SQLite database
+const sqlite = new Database(dbPath);
+sqlite.exec('PRAGMA foreign_keys = ON');
+
+const db = drizzle({
+  client: sqlite,
+  schema,
+});
+
+console.log('Running migrations...');
+
+// Run migrations
+await migrate(db, { migrationsFolder: join(process.cwd(), 'drizzle') });
+
+console.log('✅ Database initialized successfully');
+
+sqlite.close();