feat: model management improvements and folder migration

- Add model folder migration with byte-level progress tracking (backend + UI)
- Custom models directory support via VOICEBOX_MODELS_DIR env var passed to sidecar
- Hardcoded model descriptions displayed in model detail cards
- Open model folder button in storage location row
- Remove 'not downloaded' badge from model cards
- Fix server settings scroll offset for audio player
- Fix shell open permission to allow file paths
- Add normalize toggle to generation settings

app/src/components/ServerTab/ServerTab.tsx

@@ -2,12 +2,18 @@ import { ConnectionForm } from '@/components/ServerSettings/ConnectionForm';
 import { GenerationSettings } from '@/components/ServerSettings/GenerationSettings';
 import { GpuAcceleration } from '@/components/ServerSettings/GpuAcceleration';
 import { UpdateStatus } from '@/components/ServerSettings/UpdateStatus';
+import { BOTTOM_SAFE_AREA_PADDING } from '@/lib/constants/ui';
+import { cn } from '@/lib/utils/cn';
 import { usePlatform } from '@/platform/PlatformContext';
+import { usePlayerStore } from '@/stores/playerStore';
 
 export function ServerTab() {
   const platform = usePlatform();
+  const isPlayerVisible = !!usePlayerStore((state) => state.audioUrl);
   return (
-    <div className="overflow-y-auto flex flex-col">
+    <div
+      className={cn('overflow-y-auto flex flex-col', isPlayerVisible && BOTTOM_SAFE_AREA_PADDING)}
+    >
       <div className="grid gap-4 md:grid-cols-2">
         <ConnectionForm />
         <GenerationSettings />