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/src/components/lessons/instructor-form.tsx

@@ -0,0 +1,52 @@
+import { useForm } from 'react-hook-form'
+import { Button } from '@/components/ui/button'
+import { Input } from '@/components/ui/input'
+import { Label } from '@/components/ui/label'
+import { Textarea } from '@/components/ui/textarea'
+import type { Instructor } from '@/types/lesson'
+
+interface Props {
+  defaultValues?: Partial<Instructor>
+  onSubmit: (data: Record<string, unknown>) => void
+  loading?: boolean
+}
+
+export function InstructorForm({ defaultValues, onSubmit, loading }: Props) {
+  const { register, handleSubmit } = useForm({
+    defaultValues: {
+      displayName: defaultValues?.displayName ?? '',
+      bio: defaultValues?.bio ?? '',
+      instruments: defaultValues?.instruments?.join(', ') ?? '',
+    },
+  })
+
+  function handleFormSubmit(data: { displayName: string; bio: string; instruments: string }) {
+    onSubmit({
+      displayName: data.displayName,
+      bio: data.bio || undefined,
+      instruments: data.instruments
+        ? data.instruments.split(',').map((s) => s.trim()).filter(Boolean)
+        : undefined,
+    })
+  }
+
+  return (
+    <form onSubmit={handleSubmit(handleFormSubmit)} className="space-y-4">
+      <div className="space-y-2">
+        <Label htmlFor="displayName">Display Name *</Label>
+        <Input id="displayName" {...register('displayName')} required />
+      </div>
+      <div className="space-y-2">
+        <Label htmlFor="bio">Bio</Label>
+        <Textarea id="bio" {...register('bio')} rows={3} />
+      </div>
+      <div className="space-y-2">
+        <Label htmlFor="instruments">Instruments</Label>
+        <Input id="instruments" {...register('instruments')} placeholder="Piano, Guitar, Voice (comma-separated)" />
+      </div>
+      <Button type="submit" disabled={loading} className="w-full">
+        {loading ? 'Saving...' : defaultValues ? 'Save Changes' : 'Create Instructor'}
+      </Button>
+    </form>
+  )
+}