overhaul settings: split into routed sub-tabs, add server logs, changelog, reusable setting components

- Rename Server tab to Settings with horizontal sub-tab navigation (General, Generation, GPU, Logs, Changelog)
- All sub-tabs are proper routes under /settings/* with /server redirect for backwards compat
- General: connection settings, link cards (docs + discord), API reference card, app updates
- Generation: auto-chunking, crossfade, normalize, autoplay as SettingRow components
- GPU: info card with platform-aware icons (Apple logo for MPS), CUDA management, explainer text
- Logs: real-time server log viewer piped from Tauri sidecar via event system (Tauri-only)
- Changelog: parsed from CHANGELOG.md at build time via Vite virtual module plugin
- New reusable SettingRow/SettingSection components for consistent settings layout
- New Toggle (switch) UI component replacing checkboxes in settings
- Toast viewport now offsets when audio player is open
- Sidebar stays active on settings sub-routes (fuzzy matching)

app/src/components/ui/toaster.tsx

@@ -1,3 +1,4 @@
+import { usePlayerStore } from '@/stores/playerStore';
 import {
   Toast,
   ToastClose,
@@ -10,6 +11,7 @@ import { useToast } from './use-toast';
 
 export function Toaster() {
   const { toasts } = useToast();
+  const isPlayerOpen = !!usePlayerStore((s) => s.audioUrl);
 
   return (
     <ToastProvider>
@@ -23,7 +25,7 @@ export function Toaster() {
           <ToastClose />
         </Toast>
       ))}
-      <ToastViewport />
+      <ToastViewport className={isPlayerOpen ? 'sm:bottom-32' : ''} />
     </ToastProvider>
   );
 }