feat(ui-flow): preview-join-invite and create-guild templateId (Phase 663)

Route join invite preview IPC and pass templateId through create-guild.

Co-authored-by: Cursor <[email protected]>

index.js

@@ -65,7 +65,8 @@ async function dispatchUiMessage (platform, msg, hooks = {}) {
   if (t === 'create-guild') {
     await platform.createGuild({
       name: msg.name || 'My Server',
-      publicListing: msg.publicListing !== false
+      publicListing: msg.publicListing !== false,
+      templateId: msg.templateId || null
     })
     pushState()
     if (platform.activeChannelId && platform.mode === 'guild') {
@@ -995,6 +996,11 @@ async function dispatchUiMessage (platform, msg, hooks = {}) {
     }
     return true
   }
+  if (t === 'preview-join-invite') {
+    const out = await platform.previewJoinInvite(msg.code)
+    send({ type: 'join-invite-preview', result: out })
+    return true
+  }
   if (t === 'update-staged-attachment-meta') {
     await platform.updateStagedAttachmentMeta(msg.attachmentId, {
       caption: msg.caption,