fix: Filament v5 callbacks $r → $record (Plans/Subs/SuperAdmins/Companies)

+ central PWA: real PNG icons, SW registration, scope=/

- All `fn ($r) =>` and `fn (Type $r) =>` replaced with $record (Filament v5
  injects callback params by name; $r resolved to nothing)
- /pwa/admin-{192,512}.png — generated on-the-fly with GD + DejaVuSans-Bold
- /pwa/admin-icon.svg — vector favicon
- /admin-sw.js — service worker (cache shell, network-first elsewhere)
  with Service-Worker-Allowed: / header
- Manifest scope=/ + start_url=/admin → install prompt fires on Chrome/Edge/Safari
- BODY_END render hook registers SW on central panel

app/Filament/Central/Widgets/RecentTenants.php

@@ -22,7 +22,7 @@ class RecentTenants extends BaseWidget
             ->columns([
                 Tables\Columns\TextColumn::make('slug')
                     ->copyable()
-                    ->url(fn (Company $r) => CompanyResource::getUrl('view', ['record' => $r])),
+                    ->url(fn (Company $record) => CompanyResource::getUrl('view', ['record' => $record])),
                 Tables\Columns\TextColumn::make('name')->weight('bold'),
                 Tables\Columns\TextColumn::make('status')
                     ->badge()