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/auth.js

@@ -0,0 +1,35 @@
+import { jwtVerify } from 'jose'
+import { isOnsite } from './ip-check.js'
+
+const APP_SLUG = process.env.APP_SLUG || 'hk-planner'
+const secret = new TextEncoder().encode(process.env.CENTRAL_AUTH_SECRET || '')
+
+export async function requireAuth(request, reply) {
+  const token = request.cookies?.hnf_session
+  if (!token) return reply.status(401).send({ error: 'Not authenticated' })
+
+  let payload
+  try {
+    const { payload: p } = await jwtVerify(token, secret)
+    payload = p
+  } catch {
+    return reply.status(401).send({ error: 'Invalid session' })
+  }
+
+  if (!payload.apps?.includes(APP_SLUG)) {
+    return reply.status(403).send({ error: 'No permission for this app' })
+  }
+
+  if (!payload.offsite_allowed) {
+    const clientIP = request.headers['x-real-ip'] || request.ip
+    if (!(await isOnsite(clientIP))) {
+      return reply.status(403).send({ error: 'Access restricted to site network' })
+    }
+  }
+
+  request.user = {
+    email: payload.sub,
+    name: payload.name,
+    is_admin: payload.is_admin ?? false,
+  }
+}