Add ADS-B, AIS, and ALPR map layers with live CoT streaming.

Ingest aircraft and vessel tracks via OSINT feeds and tactical CoT, expose viewport-filtered SSE to the map, and add an OSM ALPR layer with tiled caching and performant marker sync.

app/components/AppShell.vue

@@ -26,6 +26,11 @@
           :user="user"
           @signout="onLogout"
         />
+        <span
+          v-else-if="authPending"
+          class="inline-block h-8 w-8"
+          aria-hidden="true"
+        />
         <NuxtLink
           v-else
           to="/login"
@@ -75,7 +80,7 @@ watch(sidebarCollapsed, (v) => {
   }
 })
 
-const { user, refresh } = useUser()
+const { user, authPending, refresh } = useUser()
 
 watch(isMobile, (mobile) => {
   if (mobile) drawerOpen.value = false