feat(waiter): install-app dialog (first visit) + "Εγκατάσταση εφαρμογής" in the side drawer

Replaces the thin bottom banner with a proper dialog (taller than wide):
app icon, four reasons to install (starts instantly, survives WiFi drops,
encrypted link, finds the server + updates itself), the three install
steps, "Λήψη εφαρμογής" and "Όχι τώρα". It opens by itself once, on the
first browser visit; closing it or tapping download marks it seen for good
(previously a 7-day dismissal, and once gone there was no way back).
Afterwards it is reachable from the side drawer, right above Settings.

Offered only where it makes sense: a browser on an Android phone (never in
the native app, on iPhones or desktops) and only if this venue's server
actually serves the APK (HEAD /downloads/xenia-waiter.apk, checked once).

Verified in Edge emulating Android / iPhone / desktop against the prod
build: auto-opens once, "Όχι τώρα" persists across reloads, drawer item
above Settings reopens it, not offered on iPhone/desktop or when the
server has no APK.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

waiter_pwa/src/App.jsx

@@ -24,7 +24,7 @@ import { SSEProvider } from './context/SSEContext'
 import ConnectivityBar from './components/ConnectivityBar'
 import AppShell from './components/AppShell'
 import UpdatePrompt from './components/UpdatePrompt'
-import InstallAppBanner from './components/InstallAppBanner'
+import InstallAppDialog from './components/InstallAppDialog'
 import VenuesPage from './pages/VenuesPage'
 import ServerRediscovery from './components/ServerRediscovery'
 import BundleSync from './components/BundleSync'
@@ -447,7 +447,7 @@ export default function App() {
           <ConnectivityBar />
           {/* Native builds ship their UI in the app bundle — no service worker to update */}
           {deliveryMode() !== 'native' && <UpdatePrompt />}
-          <InstallAppBanner />
+          <InstallAppDialog />
           {deliveryMode() === 'native' && <ServerRediscovery />}
           {deliveryMode() === 'native' && <BundleSync />}
           <Routes>

waiter_pwa/src/components/AppShell.jsx

@@ -6,6 +6,7 @@ import useNotificationSettingsStore from '../store/notificationSettingsStore'
 import useTableViewStore from '../store/tableViewStore'
 import useChatStore from '../store/chatStore'
 import useKdsReadyStore from '../store/kdsReadyStore'
+import useInstallPromptStore, { apkAvailable } from '../store/installPromptStore'
 import useOfflineQueueCount from '../hooks/useOfflineQueueCount'
 import useFailedPrintCount from '../hooks/useFailedPrintCount'
 
@@ -296,6 +297,37 @@ const DRAWER_SETTINGS_ITEM = {
   ),
 }
 
+const DRAWER_INSTALL_ITEM = {
+  key: 'install-app',
+  label: 'Εγκατάσταση εφαρμογής',
+  match: () => false,
+  icon: (
+    <svg width="22" height="22" viewBox="0 0 24 24" fill="none">
+      <path d="M12 3v12m0 0-4.5-4.5M12 15l4.5-4.5" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round"/>
+      <path d="M4 17v2a2 2 0 0 0 2 2h12a2 2 0 0 0 2-2v-2" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round"/>
+    </svg>
+  ),
+}
+
+// Browser on Android only, and only if this venue's server serves the APK
+// (the native app never shows it) — opens the install dialog.
+function InstallAppDrawerButton({ location, onClose }) {
+  const [available, setAvailable] = useState(false)
+  const show = useInstallPromptStore(s => s.show)
+  useEffect(() => {
+    apkAvailable().then(setAvailable)
+  }, [])
+  if (!available) return null
+  return (
+    <DrawerButton
+      item={DRAWER_INSTALL_ITEM}
+      location={location}
+      active={false}
+      onClick={() => { onClose(); show() }}
+    />
+  )
+}
+
 function DrawerButton({ item, location, onNavigate, active: activeProp, onClick }) {
   const active = activeProp ?? item.match(location)
   return (
@@ -392,8 +424,9 @@ function SideDrawer({ open, onClose }) {
           })}
         </div>
 
-        {/* Settings at bottom */}
+        {/* Install app + settings at bottom */}
-        <div style={{ padding: '8px 10px 16px', borderTop: '1px solid var(--border)' }}>
+        <div style={{ padding: '8px 10px 16px', borderTop: '1px solid var(--border)', display: 'flex', flexDirection: 'column', gap: 4 }}>
+          <InstallAppDrawerButton location={location} onClose={onClose} />
           <DrawerButton item={DRAWER_SETTINGS_ITEM} location={location} onNavigate={go} />
         </div>
       </div>

waiter_pwa/src/components/InstallAppBanner.jsx

@@ -1,97 +0,0 @@
-import { useEffect, useState } from 'react'
-import { deliveryMode } from '../config/server'
-
-// Shown only in plain-HTTP browser mode (http://<LAN IP>), where the page can't
-// work offline after a reload and can't be installed as a real PWA.
-//
-// The APK is served by the venue's own server (scripts/build-apk.mjs bundles the
-// release APK into the web build), so the banner appears only when that file is
-// actually there. VITE_APP_DOWNLOAD_URL overrides the location if ever needed.
-const DOWNLOAD_URL = import.meta.env.VITE_APP_DOWNLOAD_URL || '/downloads/xenia-waiter.apk'
-const DISMISS_KEY = 'install-banner-dismissed-until'
-const DISMISS_DAYS = 7
-
-function isDismissed() {
-  try {
-    return Number(localStorage.getItem(DISMISS_KEY) || 0) > Date.now()
-  } catch {
-    return false
-  }
-}
-
-export default function InstallAppBanner() {
-  const eligible = deliveryMode() === 'plain-web' && !isDismissed()
-  const [available, setAvailable] = useState(false)
-  const [hidden, setHidden] = useState(false)
-
-  useEffect(() => {
-    if (!eligible) return
-    fetch(DOWNLOAD_URL, { method: 'HEAD' })
-      .then(r => setAvailable(r.ok && !(r.headers.get('content-type') || '').includes('text/html')))
-      .catch(() => {})
-  }, [eligible])
-
-  if (!eligible || !available || hidden) return null
-
-  function dismiss() {
-    try {
-      localStorage.setItem(DISMISS_KEY, String(Date.now() + DISMISS_DAYS * 86_400_000))
-    } catch {
-      // storage unavailable — banner just reappears next load
-    }
-    setHidden(true)
-  }
-
-  return (
-    <div style={{
-      position: 'fixed',
-      bottom: 80,
-      left: 12,
-      right: 12,
-      zIndex: 9998,
-      background: 'var(--bg2)',
-      border: '1px solid var(--accent)',
-      borderRadius: 16,
-      padding: '12px 14px',
-      display: 'flex',
-      alignItems: 'center',
-      gap: 12,
-      boxShadow: '0 8px 32px rgba(0,0,0,0.4)',
-    }}>
-      <span style={{ flex: 1, fontSize: 13, color: 'var(--text)', lineHeight: 1.35 }}>
-        Για γρηγορότερη και πιο σταθερή λειτουργία, εγκαταστήστε την εφαρμογή.
-      </span>
-      <a
-        href={DOWNLOAD_URL}
-        download
-        style={{
-          background: 'var(--accent)',
-          color: '#0f172a',
-          borderRadius: 10,
-          padding: '8px 14px',
-          fontSize: 14,
-          fontWeight: 700,
-          textDecoration: 'none',
-          whiteSpace: 'nowrap',
-        }}
-      >
-        Εγκατάσταση
-      </a>
-      <button
-        onClick={dismiss}
-        aria-label="Κλείσιμο"
-        style={{
-          background: 'none',
-          border: 'none',
-          color: 'var(--muted)',
-          fontSize: 20,
-          lineHeight: 1,
-          padding: 4,
-          cursor: 'pointer',
-        }}
-      >
-        ×
-      </button>
-    </div>
-  )
-}

waiter_pwa/src/components/InstallAppDialog.jsx

@@ -0,0 +1,107 @@
+import { useEffect } from 'react'
+import useInstallPromptStore, { APK_URL, canOfferApp } from '../store/installPromptStore'
+
+const BENEFITS = [
+  { icon: '⚡', title: 'Ανοίγει αμέσως', text: 'Χωρίς φόρτωση από τον browser, σαν κανονική εφαρμογή.' },
+  { icon: '📶', title: 'Αντέχει στο WiFi', text: 'Συνεχίζει να δουλεύει όταν χάνεται για λίγο η σύνδεση.' },
+  { icon: '🔒', title: 'Ασφαλής σύνδεση', text: 'Κρυπτογραφημένη επικοινωνία με τον server του καταστήματος.' },
+  { icon: '🔄', title: 'Χωρίς ρυθμίσεις', text: 'Βρίσκει μόνη της τον server και ενημερώνεται αυτόματα.' },
+]
+
+const STEPS = [
+  'Πατήστε «Λήψη εφαρμογής».',
+  'Ανοίξτε το αρχείο και επιτρέψτε την εγκατάσταση.',
+  'Ανοίξτε το Xenia και σαρώστε ξανά το QR του καταστήματος.',
+]
+
+/**
+ * Dialog offering the Android app to browser users (see installPromptStore).
+ * Opens by itself once; afterwards from the side drawer.
+ */
+export default function InstallAppDialog() {
+  const { open, dismiss, autoOpen } = useInstallPromptStore()
+
+  useEffect(() => {
+    if (canOfferApp()) autoOpen()
+  }, [autoOpen])
+
+  if (!open) return null
+
+  return (
+    <div
+      onClick={dismiss}
+      style={{
+        position: 'fixed', inset: 0, zIndex: 10000, background: 'rgba(0,0,0,0.6)',
+        display: 'flex', alignItems: 'center', justifyContent: 'center', padding: 16,
+      }}
+    >
+      <div
+        role="dialog"
+        aria-modal="true"
+        aria-labelledby="install-app-title"
+        onClick={e => e.stopPropagation()}
+        style={{
+          width: '100%', maxWidth: 360, maxHeight: '92vh', overflowY: 'auto',
+          background: 'var(--bg2)', border: '1px solid var(--border)', borderRadius: 22,
+          boxShadow: '0 16px 48px rgba(0,0,0,0.5)', padding: '26px 22px 20px',
+          display: 'flex', flexDirection: 'column', gap: 18,
+        }}
+      >
+        <div style={{ textAlign: 'center' }}>
+          <img
+            src="/icons/icon-192.png"
+            alt=""
+            width={76}
+            height={76}
+            style={{ borderRadius: 18, boxShadow: '0 6px 20px rgba(0,0,0,0.35)' }}
+          />
+          <h2 id="install-app-title" style={{ fontSize: 20, fontWeight: 800, color: 'var(--text)', margin: '14px 0 4px' }}>
+            Εφαρμογή Xenia
+          </h2>
+          <p style={{ fontSize: 13, color: 'var(--muted)', lineHeight: 1.45 }}>
+            Εγκαταστήστε την εφαρμογή για γρηγορότερη και πιο σταθερή λειτουργία.
+          </p>
+        </div>
+
+        <div style={{ display: 'flex', flexDirection: 'column', gap: 12 }}>
+          {BENEFITS.map(b => (
+            <div key={b.title} style={{ display: 'flex', gap: 12, alignItems: 'flex-start' }}>
+              <span style={{
+                fontSize: 18, width: 36, height: 36, flexShrink: 0, borderRadius: 10,
+                background: 'var(--bg3)', display: 'flex', alignItems: 'center', justifyContent: 'center',
+              }}>
+                {b.icon}
+              </span>
+              <div>
+                <div style={{ fontSize: 14, fontWeight: 700, color: 'var(--text)' }}>{b.title}</div>
+                <div style={{ fontSize: 12.5, color: 'var(--muted)', lineHeight: 1.4 }}>{b.text}</div>
+              </div>
+            </div>
+          ))}
+        </div>
+
+        <ol style={{
+          margin: 0, padding: '12px 14px 12px 32px', borderRadius: 12, background: 'var(--bg3)',
+          fontSize: 12.5, color: 'var(--muted)', lineHeight: 1.55,
+        }}>
+          {STEPS.map(s => <li key={s}>{s}</li>)}
+        </ol>
+
+        <div style={{ display: 'flex', flexDirection: 'column', gap: 8 }}>
+          <a
+            href={APK_URL}
+            download
+            onClick={dismiss}
+            className="btn btn--accent btn--lg"
+            style={{ textDecoration: 'none', display: 'flex', alignItems: 'center', justifyContent: 'center' }}
+          >
+            Λήψη εφαρμογής
+          </a>
+          <button className="btn btn--secondary" onClick={dismiss} style={{ minHeight: 44 }}>
+            Όχι τώρα
+          </button>
+        </div>
+      </div>
+    </div>
+  )
+}

waiter_pwa/src/store/installPromptStore.js

@@ -0,0 +1,59 @@
+import { create } from 'zustand'
+import { deliveryMode } from '../config/server'
+
+/**
+ * "Install the Android app" dialog (browser mode only).
+ *
+ * It opens by itself once, the first time an Android phone opens the waiter app
+ * in a browser, and only if this venue's server actually serves the APK. Closing it or tapping
+ * download marks it as seen for good; after that it's reachable from the side
+ * drawer ("Εγκατάσταση εφαρμογής", above Settings).
+ */
+
+export const APK_URL = import.meta.env.VITE_APP_DOWNLOAD_URL || '/downloads/xenia-waiter.apk'
+const SEEN_KEY = 'install-app-prompt-seen'
+
+/** Browser on an Android phone — the only place an APK is useful. */
+export function canOfferApp() {
+  return deliveryMode() !== 'native' && /Android/i.test(navigator.userAgent)
+}
+
+let availability = null
+/** Resolves true if this server serves the APK (checked once per page load). */
+export function apkAvailable() {
+  if (!canOfferApp()) return Promise.resolve(false)
+  availability ??= fetch(APK_URL, { method: 'HEAD' })
+    // nginx answers a real 404 for a missing file under /downloads/
+    .then(r => r.ok && !(r.headers.get('content-type') || '').includes('text/html'))
+    .catch(() => false)
+  return availability
+}
+
+function wasSeen() {
+  try {
+    return localStorage.getItem(SEEN_KEY) === '1'
+  } catch {
+    return false
+  }
+}
+
+const useInstallPromptStore = create((set) => ({
+  open: false,
+  show: () => set({ open: true }),
+  /** Close and never open by itself again. */
+  dismiss: () => {
+    try {
+      localStorage.setItem(SEEN_KEY, '1')
+    } catch {
+      // storage unavailable — it may open once more on the next visit
+    }
+    set({ open: false })
+  },
+  /** First visit: open once if the APK is there and the dialog wasn't seen yet. */
+  autoOpen: async () => {
+    if (wasSeen() || !(await apkAvailable())) return
+    set({ open: true })
+  },
+}))
+
+export default useInstallPromptStore