Implement multi-step registration process: Add step indicators, error handling, and payment processing for membership registration. Enhance form validation and user feedback with success and error messages. Refactor state management for improved clarity and maintainability.

server/models/member.js

@@ -22,8 +22,21 @@ const memberSchema = new mongoose.Schema({
     enum: getValidContributionValues(),
     required: true
   },
+  status: {
+    type: String,
+    enum: ['pending_payment', 'active', 'suspended', 'cancelled'],
+    default: 'pending_payment'
+  },
   helcimCustomerId: String,
   helcimSubscriptionId: String,
+  paymentMethod: {
+    type: String,
+    enum: ['card', 'bank', 'none'],
+    default: 'none'
+  },
+  subscriptionStartDate: Date,
+  subscriptionEndDate: Date,
+  nextBillingDate: Date,
   slackInvited: { type: Boolean, default: false },
   createdAt: { type: Date, default: Date.now },
   lastLogin: Date