Deep Research and Posterverse: the open tab is in the address, written by the site's router

- Both apps are told urlOwner 'host' and send 'dxm-address' when their open tab changes; the page's router
  writes it: a tab click is a new history entry, the app's first paint replaces the current one.
- So a shared link or a reload opens the same tab, and Back, Forward and the language switch keep it.

app/pages/deep-research/index.vue

@@ -99,6 +99,18 @@ function onLanguageRequest(e: Event) {
   navigateTo(url.pathname + url.search + url.hash)
 }
 
+// THE ADDRESS (shareable pages): this site's router owns the address, so the app is told urlOwner 'host' and, when the
+// open tab changes, it sends a 'dxm-address' {href, push} instead of writing history itself. A reader's tab click is a
+// new history entry (push); the app's first paint replaces the current one (so a shared link or a reload keeps the
+// tab). The router writes it, so Back, Forward and the language switch keep the tab; Back/Forward never send one.
+const router = useRouter()
+function onAddress(e: Event) {
+  const d = (e as CustomEvent<{ href?: string, push?: boolean }>).detail
+  if (!d || typeof d.href !== 'string' || !d.href.startsWith('/') || d.href.startsWith('//')) return
+  if (d.push) router.push(d.href).catch(() => {})
+  else router.replace(d.href).catch(() => {})
+}
+
 onMounted(() => {
   gallery = document.createElement('doxa-maps-spa')
   // Every embed URL is built at RUNTIME from the origin serving this page, so the same build works on
@@ -116,10 +128,13 @@ onMounted(() => {
   const galleryConfig: Record<string, unknown> = {}
   // The keyless MapLibre engine, always: the app needs no token and no setting.
   galleryConfig.provider = 'maplibre'
+  // the site's router writes the address (onAddress, above)
+  galleryConfig.urlOwner = 'host'
   gallery.setAttribute('provider', 'maplibre')
   gallery.setAttribute('profile-config', JSON.stringify(galleryConfig))
   gallery.addEventListener('tab-change', onTabChange)
   gallery.addEventListener('doxa-language-request', onLanguageRequest)
+  gallery.addEventListener('dxm-address', onAddress)
   host.value?.appendChild(gallery)
   // its script, revalidated (above) and then added at its plain address, once per page load
   if (!customElements.get('doxa-maps-spa') && !document.querySelector(`script[src="${GALLERY_SCRIPT}"]`)) {

app/pages/posterverse/index.vue

@@ -98,6 +98,18 @@ function onLanguageRequest(e: Event) {
   navigateTo(url.pathname + url.search + url.hash)
 }
 
+// THE ADDRESS (shareable pages): this site's router owns the address, so the app is told urlOwner 'host' and, when the
+// open tab changes, it sends a 'dxm-address' {href, push} instead of writing history itself. A reader's tab click is a
+// new history entry (push); the app's first paint replaces the current one (so a shared link or a reload keeps the
+// tab). The router writes it, so Back, Forward and the language switch keep the tab; Back/Forward never send one.
+const router = useRouter()
+function onAddress(e: Event) {
+  const d = (e as CustomEvent<{ href?: string, push?: boolean }>).detail
+  if (!d || typeof d.href !== 'string' || !d.href.startsWith('/') || d.href.startsWith('//')) return
+  if (d.push) router.push(d.href).catch(() => {})
+  else router.replace(d.href).catch(() => {})
+}
+
 onMounted(() => {
   shell = document.createElement('posterverse-app')
   // Every embed URL is built at RUNTIME from the origin serving this page, so the same build works on
@@ -112,11 +124,13 @@ onMounted(() => {
   shell.setAttribute('home-href', homeHref())
   shell.setAttribute('home-label', homeLabel())
   // The keyless MapLibre engine, always: the app needs no token and no setting.
-  const shellConfig: Record<string, unknown> = { provider: 'maplibre' }
+  // urlOwner 'host': the site's router writes the address (onAddress, above)
+  const shellConfig: Record<string, unknown> = { provider: 'maplibre', urlOwner: 'host' }
   shell.setAttribute('provider', 'maplibre')
   shell.setAttribute('profile-config', JSON.stringify(shellConfig))
   shell.addEventListener('tab-change', onTabChange)
   shell.addEventListener('doxa-language-request', onLanguageRequest)
+  shell.addEventListener('dxm-address', onAddress)
   host.value?.appendChild(shell)
   // its script, revalidated (above) and then added at its plain address, once per page load
   if (!customElements.get('posterverse-app') && !document.querySelector(`script[src="${POSTERVERSE_SCRIPT}"]`)) {