Show installed app handoff during signup

public/sw.js

@@ -1,4 +1,4 @@
-const CACHE_NAME = 'l484-pwa-v8'
+const CACHE_NAME = 'l484-pwa-v9'
 const APP_SHELL = [
   '/',
   '/manifest.webmanifest',

src/App.vue

@@ -369,12 +369,14 @@ const canContinue = computed(() => {
   return true
 })
 const pwaInstallTitle = computed(() => {
+  if (pwaInstallMessage.value) return 'Open the L484 app'
   if (isPwaStandalone.value) return 'PWA installed'
   if (installPlatform.value === 'ios') return 'Install L484 on iPhone'
   if (installPlatform.value === 'android') return 'Install L484 on Android'
   return 'Install L484 on this device'
 })
 const pwaInstallCopy = computed(() => {
+  if (pwaInstallMessage.value) return 'Continue signup in the installed app. It will start at name entry.'
   if (installPlatform.value === 'ios') return 'Use Safari, tap Share, then Add to Home Screen. Reopen L484 from the new app icon to continue signup.'
   return 'Press Install app to open the browser install prompt.'
 })
@@ -724,10 +726,10 @@ const clampSignupStep = (step) => {
   return Math.min(5, Math.max(0, Math.round(numericStep)))
 }
 
-const saveSignupDraft = () => {
+const saveSignupDraft = (step = signupStep.value) => {
   if (currentMember.value || signupStep.value === 5) return
   localStorage.setItem(SIGNUP_DRAFT_KEY, JSON.stringify({
-    step: clampSignupStep(signupStep.value),
+    step: clampSignupStep(step),
     form: {
       fullName: form.fullName,
       email: form.email,
@@ -785,8 +787,8 @@ const handleBeforeInstallPrompt = (event) => {
 
 const handlePwaInstalled = () => {
   deferredInstallPrompt.value = null
-  signupStep.value = 2
-  saveSignupDraft()
+  signupStep.value = 1
+  saveSignupDraft(2)
   pwaInstallMessage.value = 'Installed. Open L484 from your homescreen to continue.'
   refreshPwaStandalone()
 }
@@ -807,8 +809,8 @@ const handlePwaInstallPrimary = async () => {
     await promptEvent.prompt()
     const choice = await promptEvent.userChoice.catch(() => null)
     if (choice?.outcome === 'accepted') {
-      signupStep.value = 2
-      saveSignupDraft()
+      signupStep.value = 1
+      saveSignupDraft(2)
       pwaInstallMessage.value = 'Installed. Open L484 from your homescreen to continue.'
       return
     }
@@ -817,8 +819,8 @@ const handlePwaInstallPrimary = async () => {
   }
 
   if (installPlatform.value === 'desktop' || installPlatform.value === 'android') {
-    signupStep.value = 2
-    saveSignupDraft()
+    signupStep.value = 1
+    saveSignupDraft(2)
     pwaInstallMessage.value = 'L484 may already be installed on this device. Open the installed app to finish signup.'
     return
   }