feat(frontend): gate first run on needs-admin so a fresh instance shows the wizard

A fresh install landed on the anonymous dashboard instead of prompting to create
the first admin, so an operator had no way to discover /setup.

The router now asks /api/setup/needs-admin before rendering any unauthenticated
route and redirects to /login?firstrun=1 while no user exists. The result is
cached in a composable so it costs one request per session, and the lookup fails
open (a backend that cannot answer must not lock the login screen). Racing it
against a 4s timeout keeps a slow or hung backend from blocking the first paint.

Login.vue clears the flag after creating the admin so the gate stops firing
without a reload.

frontend/src/composables/setupState.js

@@ -2,7 +2,7 @@
 // admin into the /setup wizard. Defaults to "complete" so the wizard never
 // flashes before the real value loads.
 import { ref } from 'vue'
-import { settingsApi } from '../api'
+import { settingsApi, setupApi } from '../api'
 
 export const setupComplete = ref(true)
 // Session-only: a fresh admin who clicks "Skip for now" is not nagged again
@@ -26,3 +26,31 @@ export async function refreshSetupState() {
   loaded.value = true
   return setupComplete.value
 }
+
+// First run, before any user exists. Defaults to false so the app never flashes
+// the create-admin screen at an established site while this loads.
+export const needsAdmin = ref(false)
+const adminLoaded = ref(false)
+
+export function isNeedsAdminLoaded() {
+  return adminLoaded.value
+}
+
+export async function refreshNeedsAdmin() {
+  try {
+    const response = await setupApi.needsAdmin()
+    needsAdmin.value = response.data?.data?.needsadmin === true
+  } catch (err) {
+    // Fail open: if we cannot tell, assume an admin exists rather than trap
+    // everyone behind a create-admin screen they cannot complete.
+    needsAdmin.value = false
+  }
+  adminLoaded.value = true
+  return needsAdmin.value
+}
+
+// Called after the first admin is created so the gate stops firing.
+export function clearNeedsAdmin() {
+  needsAdmin.value = false
+  adminLoaded.value = true
+}

frontend/src/router/index.js

@@ -2,7 +2,8 @@ import { createRouter, createWebHistory } from 'vue-router'
 import { useAuthStore } from '../stores/auth'
 import AppLayout from '../views/AppLayout.vue'
 import SettingsLayout from '../views/settings/SettingsLayout.vue'
-import { setupComplete, setupSkipped, isSetupLoaded, refreshSetupState } from '../composables/setupState'
+import { setupComplete, setupSkipped, isSetupLoaded, refreshSetupState,
+         needsAdmin, isNeedsAdminLoaded, refreshNeedsAdmin } from '../composables/setupState'
 import { loadEnabledPlugins, isPluginEnabled } from '../composables/enabledPlugins'
 import { useToast } from '../composables/toast'
 import { getFacilityName } from '../utils/siteSettings'
@@ -196,6 +197,24 @@ router.afterEach(() => {
 router.beforeEach(async (to, from, next) => {
   const authStore = useAuthStore()
 
+  // FIRST RUN: until an admin exists, nothing else in the app is useful. Without
+  // this, a fresh instance serves an anonymous dashboard and the operator has no
+  // indication that setup is unfinished (they must guess their way to /login).
+  // Unauthenticated only, so it costs an established site nothing.
+  if (!authStore.isAuthenticated && to.path !== '/login') {
+    if (!isNeedsAdminLoaded()) {
+      // Bounded like the plugin gate: a hung request must not hold navigation
+      // open. refreshNeedsAdmin fails open on error.
+      await Promise.race([
+        refreshNeedsAdmin(),
+        new Promise(resolve => setTimeout(resolve, 4000)),
+      ])
+    }
+    if (needsAdmin.value) {
+      return next({ path: '/login', query: { firstrun: '1' } })
+    }
+  }
+
   if (to.meta.requiresAuth && !authStore.isAuthenticated) {
     // Remember where they were headed so login can send them back there.
     return next({ path: '/login', query: { redirect: to.fullPath } })

frontend/src/views/Login.vue

@@ -51,6 +51,7 @@ import { ref, onMounted } from 'vue'
 import { useRouter, useRoute } from 'vue-router'
 import { useAuthStore } from '../stores/auth'
 import { setupApi } from '../api'
+import { clearNeedsAdmin } from '../composables/setupState'
 import { getSiteLogo } from '../utils/siteSettings'
 import { withBase, stripBase } from '../utils/basePath'
 
@@ -102,6 +103,7 @@ async function handleCreateAdmin() {
   loading.value = true
   try {
     await setupApi.createAdmin({ username: username.value, email: email.value, password: password.value })
+    clearNeedsAdmin()   // an admin now exists; stop the first-run gate firing
     // Log straight in with the new credentials, then on to the setup wizard.
     const result = await authStore.login(username.value, password.value)
     if (result.success) router.push('/setup')