feat: refactor role system to is_admin flag, add Badge component, fix native dialogs

- Separate admin identity from role: viewer|model + is_admin boolean flag
- DB migration 0001_is_admin: adds column, migrates former admin role users
- Update ACL helpers, auth session, GraphQL types and all resolvers
- Admin layout guard and header links check is_admin instead of role
- Admin users table: show Admin badge next to name, remove admin from role select
- Admin user edit page: is_admin checkbox toggle
- Install shadcn Badge component; use in admin users table
- Fix duplicate photo keys in adminGetUser resolver
- Replace confirm() in /me recordings with Dialog component

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

packages/frontend/src/routes/me/+page.svelte

@@ -18,6 +18,7 @@
   import * as Alert from "$lib/components/ui/alert";
   import { toast } from "svelte-sonner";
   import { deleteRecording, removeFile, updateProfile, uploadFile } from "$lib/services";
+  import * as Dialog from "$lib/components/ui/dialog";
   import { Textarea } from "$lib/components/ui/textarea";
   import Meta from "$lib/components/meta/meta.svelte";
   import { TagsInput } from "$lib/components/ui/tags-input";
@@ -27,6 +28,9 @@
   const { data } = $props();
 
   let recordings = $state(data.recordings);
+  let deleteTarget = $state<string | null>(null);
+  let deleteOpen = $state(false);
+  let deleting = $state(false);
 
   let activeTab = $state("settings");
 
@@ -153,17 +157,24 @@
     }
   }
 
-  async function handleDeleteRecording(id: string) {
-    if (!confirm($_("me.recordings.delete_confirm"))) {
-      return;
-    }
+  function handleDeleteRecording(id: string) {
+    deleteTarget = id;
+    deleteOpen = true;
+  }
 
+  async function confirmDeleteRecording() {
+    if (!deleteTarget) return;
+    deleting = true;
     try {
-      await deleteRecording(id);
-      recordings = recordings.filter((r) => r.id !== id);
+      await deleteRecording(deleteTarget);
+      recordings = recordings.filter((r) => r.id !== deleteTarget);
       toast.success($_("me.recordings.delete_success"));
+      deleteOpen = false;
+      deleteTarget = null;
     } catch {
       toast.error($_("me.recordings.delete_error"));
+    } finally {
+      deleting = false;
     }
   }
 
@@ -641,3 +652,18 @@
     </Tabs>
   </div>
 </div>
+
+<Dialog.Root bind:open={deleteOpen}>
+  <Dialog.Content>
+    <Dialog.Header>
+      <Dialog.Title>{$_("me.recordings.delete_confirm")}</Dialog.Title>
+      <Dialog.Description>This cannot be undone.</Dialog.Description>
+    </Dialog.Header>
+    <Dialog.Footer>
+      <Button variant="outline" onclick={() => (deleteOpen = false)}>Cancel</Button>
+      <Button variant="destructive" disabled={deleting} onclick={confirmDeleteRecording}>
+        {deleting ? "Deleting…" : "Delete"}
+      </Button>
+    </Dialog.Footer>
+  </Dialog.Content>
+</Dialog.Root>