feat: Quota overage system, updated tier pricing, and communication addons

Quota Overage System:
- Add QuotaOverage model for tracking resource/user quota overages
- Implement 30-day grace period with email notifications (immediate, 7-day, 1-day)
- Add QuotaWarningBanner component in BusinessLayout
- Add QuotaSettings page for managing overages and archiving resources
- Add Celery tasks for automated quota checks and expiration handling
- Add quota management API endpoints

Updated Tier Pricing (Stripe: 2.9% + $0.30):
- Free: No payments (requires addon)
- Starter: 4% + $0.40
- Professional: 3.5% + $0.35
- Business: 3.25% + $0.32
- Enterprise: 3% + $0.30

New Subscription Addons:
- Online Payments ($5/mo + 5% + $0.50) - for Free tier
- SMS Notifications ($10/mo) - enables SMS reminders
- Masked Calling ($15/mo) - enables anonymous calling

BusinessEditModal Improvements:
- Increased width to match PlanModal (max-w-3xl)
- Added all tier options with auto-update on tier change
- Added limits configuration and permissions sections

Backend Fixes:
- Fixed SubscriptionPlan serializer to include all communication fields
- Allow blank business_tier for addon plans
- Added migration for business_tier field changes

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

frontend/src/api/quota.ts

@@ -0,0 +1,103 @@
+/**
+ * Quota Management API
+ */
+
+import apiClient from './client';
+import { QuotaOverage } from './auth';
+
+export interface QuotaUsage {
+  current: number;
+  limit: number;
+  display_name: string;
+}
+
+export interface QuotaStatus {
+  active_overages: QuotaOverage[];
+  usage: Record<string, QuotaUsage>;
+}
+
+export interface QuotaResource {
+  id: number;
+  name: string;
+  email?: string;
+  role?: string;
+  type?: string;
+  duration?: number;
+  price?: string;
+  created_at: string | null;
+  is_archived: boolean;
+  archived_at: string | null;
+}
+
+export interface QuotaResourcesResponse {
+  quota_type: string;
+  resources: QuotaResource[];
+}
+
+export interface ArchiveResponse {
+  archived_count: number;
+  current_usage: number;
+  limit: number;
+  is_resolved: boolean;
+}
+
+export interface QuotaOverageDetail extends QuotaOverage {
+  status: string;
+  created_at: string;
+  initial_email_sent_at: string | null;
+  week_reminder_sent_at: string | null;
+  day_reminder_sent_at: string | null;
+  archived_resource_ids: number[];
+}
+
+/**
+ * Get current quota status
+ */
+export const getQuotaStatus = async (): Promise<QuotaStatus> => {
+  const response = await apiClient.get<QuotaStatus>('/quota/status/');
+  return response.data;
+};
+
+/**
+ * Get resources for a specific quota type
+ */
+export const getQuotaResources = async (quotaType: string): Promise<QuotaResourcesResponse> => {
+  const response = await apiClient.get<QuotaResourcesResponse>(`/quota/resources/${quotaType}/`);
+  return response.data;
+};
+
+/**
+ * Archive resources to resolve quota overage
+ */
+export const archiveResources = async (
+  quotaType: string,
+  resourceIds: number[]
+): Promise<ArchiveResponse> => {
+  const response = await apiClient.post<ArchiveResponse>('/quota/archive/', {
+    quota_type: quotaType,
+    resource_ids: resourceIds,
+  });
+  return response.data;
+};
+
+/**
+ * Unarchive a resource
+ */
+export const unarchiveResource = async (
+  quotaType: string,
+  resourceId: number
+): Promise<{ success: boolean; resource_id: number }> => {
+  const response = await apiClient.post('/quota/unarchive/', {
+    quota_type: quotaType,
+    resource_id: resourceId,
+  });
+  return response.data;
+};
+
+/**
+ * Get details for a specific overage
+ */
+export const getOverageDetail = async (overageId: number): Promise<QuotaOverageDetail> => {
+  const response = await apiClient.get<QuotaOverageDetail>(`/quota/overages/${overageId}/`);
+  return response.data;
+};