fix: resolve all frontend lint errors and warnings

Replace all `any` types with proper types across 36 files:
- TanStack Router search params: `{} as Record<string, unknown>`
- API response pagination: proper typed interface
- DataTable column casts: remove unnecessary `as any`
- Function params and event handlers: use specific types
- Remove unused imports and variables in POS components

Frontend lint now passes with 0 errors and 0 warnings.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/admin/src/routes/_authenticated/lessons/templates/$templateId.tsx

@@ -18,7 +18,7 @@ import { Dialog, DialogContent, DialogHeader, DialogTitle } from '@/components/u
 import { ArrowLeft, Search, X, Zap } from 'lucide-react'
 import { toast } from 'sonner'
 import { useAuthStore } from '@/stores/auth.store'
-import type { LessonPlanTemplate } from '@/types/lesson'
+import type { Enrollment, LessonPlanTemplate } from '@/types/lesson'
 import type { MemberWithAccount } from '@/api/members'
 
 export const Route = createFileRoute('/_authenticated/lessons/templates/$templateId')({
@@ -42,7 +42,7 @@ function TemplateDetailPage() {
   return (
     <div className="space-y-6 max-w-3xl">
       <div className="flex items-center gap-3">
-        <Button variant="ghost" size="sm" onClick={() => navigate({ to: '/lessons/templates', search: {} as any })}>
+        <Button variant="ghost" size="sm" onClick={() => navigate({ to: '/lessons/templates', search: {} as Record<string, unknown> })}>
           <ArrowLeft className="h-4 w-4" />
         </Button>
         <div className="flex-1">
@@ -93,7 +93,7 @@ function TemplateDetailPage() {
 
 // ─── Edit Form ────────────────────────────────────────────────────────────────
 
-function EditTemplateForm({ template, templateId, queryClient }: { template: LessonPlanTemplate; templateId: string; queryClient: any }) {
+function EditTemplateForm({ template, templateId, queryClient }: { template: LessonPlanTemplate; templateId: string; queryClient: ReturnType<typeof useQueryClient> }) {
   const [name, setName] = useState(template.name)
   const [description, setDescription] = useState(template.description ?? '')
   const [instrument, setInstrument] = useState(template.instrument ?? '')
@@ -218,7 +218,7 @@ function InstantiateDialog({ template, templateId, open, onClose }: {
       }),
     onSuccess: (plan) => {
       toast.success('Plan created from template')
-      navigate({ to: '/lessons/plans/$planId', params: { planId: plan.id }, search: {} as any })
+      navigate({ to: '/lessons/plans/$planId', params: { planId: plan.id }, search: {} as Record<string, unknown> })
     },
     onError: (err) => toast.error(err.message),
   })
@@ -293,7 +293,7 @@ function InstantiateDialog({ template, templateId, open, onClose }: {
                 <SelectTrigger><SelectValue placeholder="Not linked to enrollment" /></SelectTrigger>
                 <SelectContent>
                   <SelectItem value="none">Not linked to enrollment</SelectItem>
-                  {enrollments.map((e: any) => (
+                  {enrollments.map((e: Enrollment) => (
                     <SelectItem key={e.id} value={e.id}>Enrollment {e.id.slice(-6)}</SelectItem>
                   ))}
                 </SelectContent>