fix: replace autofocus attribute with use:action to resolve a11y warning

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

Author: centdix

frontend/src/lib/CreateWorktreeDialog.svelte

@@ -32,6 +32,8 @@
   let profile = $state(savedProfile ?? "Full");
   let saveDefault = $state(false);
 
+  function focus(node: HTMLElement) { node.focus(); }
+
   $effect(() => {
     if (!profiles.some(p => p.name === profile)) {
       profile = defaultProfile;
@@ -61,7 +63,7 @@
       <textarea
         id="wt-prompt"
         rows="3"
-        autofocus
+        use:focus
         class="w-full px-2.5 py-1.5 rounded-md border border-edge bg-surface text-primary text-[13px] placeholder:text-muted/50 outline-none focus:border-accent resize-y"
         placeholder="Describe the task for the agent..."
         bind:value={prompt}