Ship signup sheet, subscribe reminders, cover crop, and theme updates.

Wire real WeChat app config, prefer activity cover over posters, and add admin cover cropping for the home banner.

Co-authored-by: Cursor <cursoragent@cursor.com>

miniprogram/pages/detail/detail.js

@@ -5,7 +5,8 @@ const activityUtil = require('../../utils/activity')
 Page({
   data: {
     activity: null,
-    failed: false
+    failed: false,
+    signupOpen: false
   },
 
   onLoad(query) {
@@ -36,8 +37,13 @@ Page({
     activityUtil.openMap(this.data.activity)
   },
 
-  goSignup() {
-    activityUtil.goSignup(this.data.activity)
+  openSignup() {
+    if (!this.data.activity || this.data.activity.status === 'past') return
+    this.setData({ signupOpen: true })
+  },
+
+  closeSignup() {
+    this.setData({ signupOpen: false })
   },
 
   goHome() {