refactor: restructure server settings and models UI

- Split chunking/crossfade sliders into dedicated GenerationSettings card
- Merge connection status badges into ConnectionForm (remove ServerStatus card)
- 2-column grid layout for the entire settings page
- GPU Acceleration: remove icon, badge, and MLX info card
- Models: merge 'Other Voice Models' into single 'Voice Generation' list
- Model detail: remove 'Downloaded' badge, border above actions, swap
  badges above stats row, match disk size font to stats

app/src/components/ServerTab/ServerTab.tsx

@@ -1,19 +1,19 @@
 import { ConnectionForm } from '@/components/ServerSettings/ConnectionForm';
+import { GenerationSettings } from '@/components/ServerSettings/GenerationSettings';
 import { GpuAcceleration } from '@/components/ServerSettings/GpuAcceleration';
-import { ServerStatus } from '@/components/ServerSettings/ServerStatus';
 import { UpdateStatus } from '@/components/ServerSettings/UpdateStatus';
 import { usePlatform } from '@/platform/PlatformContext';
 
 export function ServerTab() {
   const platform = usePlatform();
   return (
-    <div className="space-y-4 overflow-y-auto flex flex-col">
+    <div className="overflow-y-auto flex flex-col">
       <div className="grid gap-4 md:grid-cols-2">
         <ConnectionForm />
-        <ServerStatus />
+        <GenerationSettings />
+        {platform.metadata.isTauri && <GpuAcceleration />}
+        {platform.metadata.isTauri && <UpdateStatus />}
       </div>
-      {platform.metadata.isTauri && <GpuAcceleration />}
-      {platform.metadata.isTauri && <UpdateStatus />}
       <div className="py-8 text-center text-sm text-muted-foreground">
         Created by{' '}
         <a