improved component composition and added tests.

src/App.svelte

@@ -2,8 +2,7 @@
   /**
    * Shell: restore the session, then render chrome plus whichever route matched.
    */
-  import { router } from '$lib/router.svelte'
-  import { session } from '$lib/stores/session.svelte'
+  import { useAppServices } from '$lib/app-services'
   import SiteHeader from '$components/chrome/SiteHeader.svelte'
   import SiteNav from '$components/chrome/SiteNav.svelte'
   import SiteFooter from '$components/chrome/SiteFooter.svelte'
@@ -20,11 +19,15 @@
   import NotFound from '$routes/NotFound.svelte'
   import type { TimelineKind } from '$lib/api/endpoints'
 
+  const { router, session } = useAppServices()
+
   let booted = $state(false)
 
   $effect(() => {
+    let active = true
     void (async () => {
       const landing = await session.restore()
+      if (!active) return
       booted = true
 
       if (landing) {
@@ -34,6 +37,9 @@
         router.replace('#/login')
       }
     })()
+    return () => {
+      active = false
+    }
   })
 
   const route = $derived(router.current)