Initial commit: HK Planner app

Housekeeping workload and hours planning app — port of the WP hotel
housekeeping hours calculator plugin. 7-day occupancy planner with
Newbook PMS integration, staff rota, time requirements, and pickup tracking.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/src/db.js

@@ -0,0 +1,26 @@
+import pg from 'pg'
+
+const { Pool } = pg
+export const pool = new Pool({ connectionString: process.env.DATABASE_URL })
+
+export async function initDb() {
+  await pool.query(`
+    CREATE TABLE IF NOT EXISTS hk_config (
+      key   TEXT PRIMARY KEY,
+      value JSONB NOT NULL DEFAULT 'null'::jsonb
+    )
+  `)
+}
+
+export async function getConfig(key, defaultVal = null) {
+  const { rows } = await pool.query('SELECT value FROM hk_config WHERE key = $1', [key])
+  return rows.length ? rows[0].value : defaultVal
+}
+
+export async function setConfig(key, value) {
+  await pool.query(
+    `INSERT INTO hk_config (key, value) VALUES ($1, $2::jsonb)
+     ON CONFLICT (key) DO UPDATE SET value = EXCLUDED.value`,
+    [key, JSON.stringify(value)]
+  )
+}