Add lessons module, rate cycles, EC2 deploy scripts, and help content

- Lessons module: lesson types, instructors, schedule slots, enrollments,
  sessions (list + week grid view), lesson plans, grading scales, templates
- Rate cycles: replace monthly_rate with billing_interval + billing_unit on
  enrollments; add weekly/monthly/quarterly rate presets to lesson types and
  schedule slots with auto-fill on enrollment form
- Member detail page: tabbed layout for details, identity documents, enrollments
- Sessions week view: custom 7-column grid replacing react-big-calendar
- Music store seed: instructors, lesson types, slots, enrollments, sessions,
  grading scale, lesson plan template
- Scrollbar styling: themed to match sidebar/app palette
- deploy/: EC2 setup and redeploy scripts, nginx config, systemd service
- Help: add Lessons category (overview, types, instructors, slots, enrollments,
  sessions, plans/grading); collapsible sidebar with independent scroll;
  remove POS/accounting references from docs

packages/admin/package.json

@@ -10,8 +10,8 @@
     "lint": "eslint ."
   },
   "dependencies": {
-    "@lunarfront/shared": "workspace:*",
     "@hookform/resolvers": "^5.2.2",
+    "@lunarfront/shared": "workspace:*",
     "@radix-ui/react-dialog": "^1.1.14",
     "@radix-ui/react-dropdown-menu": "^2.1.15",
     "@radix-ui/react-label": "^2.1.7",
@@ -21,12 +21,15 @@
     "@radix-ui/react-tabs": "^1.1.12",
     "@tanstack/react-query": "^5.75.5",
     "@tanstack/react-router": "^1.121.0",
+    "@types/react-big-calendar": "^1.16.3",
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",
+    "date-fns": "^4.1.0",
     "jspdf": "^4.2.1",
     "lucide-react": "^1.7.0",
     "radix-ui": "^1.4.3",
     "react": "^19.1.0",
+    "react-big-calendar": "^1.19.4",
     "react-dom": "^19.1.0",
     "react-hook-form": "^7.72.0",
     "sonner": "^2.0.3",