fix(auth): clear stale credential error after github re-auth

The 401 flag and cached repo list were module-level and only reset
after a 20-min stale window, so re-authenticating left the
"credentials are invalid or expired" message pinned on. Watch the
access token: reset state and refetch on change. Also await
saveCredentials before redirecting so refs are settled.

src/components/AuthorizeUser.vue

@@ -19,8 +19,7 @@ onBeforeMount(async () => {
     if ("error" in token) {
       hasError.value = true
     } else {
-      token.access_token
-      saveCredentials(token)
+      await saveCredentials(token)
     }
 
     router.replace({ name: "Home" })