feat: add database initialization script command

package.json

@@ -10,6 +10,7 @@
     "type-check": "tsc --noEmit",
     "test:db": "node scripts/test-db.js",
     "init:backend": "chmod +x scripts/init-backend.sh && ./scripts/init-backend.sh",
+    "init:db": "node scripts/init-db.js",
     "sync:arch": "npx tsx scripts/sync-arch.ts"
   },
   "dependencies": {

scripts/init-db.js

@@ -0,0 +1,41 @@
+#!/usr/bin/env node
+
+const { Pool } = require('pg')
+
+const DB_HOST = process.env.DB_HOST || 'localhost'
+const DB_PORT = parseInt(process.env.DB_PORT || '5432', 10)
+const DB_USER = process.env.DB_USER || 'postgres'
+const DB_PASSWORD = process.env.DB_PASSWORD || ''
+const DB_NAME = process.env.DB_NAME || 'repohub'
+
+async function main() {
+  // Connect to default 'postgres' database to create DB if missing
+  const admin = new Pool({
+    host: DB_HOST,
+    port: DB_PORT,
+    database: 'postgres',
+    user: DB_USER,
+    password: DB_PASSWORD,
+  })
+
+  try {
+    console.log(`🔍 Ensuring database "${DB_NAME}" exists on ${DB_HOST}:${DB_PORT} ...`)
+    await admin.query(`CREATE DATABASE ${DB_NAME};`)
+    console.log(`✅ Created database "${DB_NAME}"`)
+  } catch (err) {
+    // 42P04 = duplicate_database
+    if (err && err.code === '42P04') {
+      console.log(`ℹ️ Database "${DB_NAME}" already exists`)
+    } else {
+      console.error('❌ Failed to create database:', err)
+      process.exitCode = 1
+    }
+  } finally {
+    await admin.end().catch(() => {})
+  }
+}
+
+main().catch((e) => {
+  console.error('❌ init:db failed:', e)
+  process.exit(1)
+})