Fix all ESLint errors: remove unused imports, replace any types

- Remove ~60 unused imports and variables across 88 files
- Replace ~80 `any` type annotations with proper types (unknown,
  Record<string, unknown>, or specific types)
- Prefix unused callback args with underscore
- Fix unescaped JSX entities
- Lint now passes cleanly (0 errors, 2 intentional img warnings)

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

src/components/admin/webhooks/webhook-event-selector.tsx

@@ -2,7 +2,7 @@
 
 import { Checkbox } from '@/components/ui/checkbox';
 import { Label } from '@/components/ui/label';
-import { WEBHOOK_EVENTS, type WebhookEvent } from '@/lib/services/webhook-event-map';
+import { type WebhookEvent } from '@/lib/services/webhook-event-map';
 
 // ─── Event Groups ─────────────────────────────────────────────────────────────