feat(leads): add Lead Manager module with full admin and consumer endpoints

- Lead model in admin_api with status/priority/source/assigned_to fields
- Admin API: metrics, list, detail, update views at /api/v1/leads/
- Consumer API: public ScheduleCallView at /api/leads/schedule-call/
- RBAC: 'leads' module registered in ALL_MODULES and StaffProfile scopes
- Migration 0003_lead with indexes on status, priority, created_at, email

CHANGELOG.md

@@ -5,6 +5,22 @@ Format follows [Keep a Changelog](https://keepachangelog.com/en/1.0.0/), version
 
 ---
 
+## [1.9.0] — 2026-04-07
+
+### Added
+- **Lead Manager** — new `Lead` model in `admin_api` for tracking Schedule-a-Call form submissions and sales inquiries
+  - Fields: name, email, phone, event_type, message, status (new/contacted/qualified/converted/closed), source (schedule_call/website/manual), priority (low/medium/high), assigned_to (FK User), notes
+  - Migration `admin_api/0003_lead` with indexes on status, priority, created_at, email
+- **Consumer endpoint** `POST /api/leads/schedule-call/` — public (AllowAny, CSRF-exempt) endpoint for the Schedule a Call modal; creates Lead with status=new, source=schedule_call
+- **Admin API endpoints** (all IsAuthenticated):
+  - `GET /api/v1/leads/metrics/` — total, new today, counts per status
+  - `GET /api/v1/leads/` — paginated list with filters (status, priority, source, search, date_from, date_to)
+  - `GET /api/v1/leads/<id>/` — single lead detail
+  - `PATCH /api/v1/leads/<id>/update/` — update status, priority, assigned_to, notes
+- **RBAC**: `leads` added to `ALL_MODULES`, `get_allowed_modules()`, and `StaffProfile.SCOPE_TO_MODULE`
+
+---
+
 ## [1.8.3] — 2026-04-06
 
 ### Fixed