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)

web/src/platform/lifecycle.ts

@@ -1,4 +1,4 @@
-import type { PlatformLifecycle } from '@/platform/types';
+import type { PlatformLifecycle, ServerLogEntry } from '@/platform/types';
 
 class WebLifecycle implements PlatformLifecycle {
   onServerReady?: () => void;
@@ -27,6 +27,11 @@ class WebLifecycle implements PlatformLifecycle {
   async setupWindowCloseHandler(): Promise<void> {
     // No-op for web - no window close handling needed
   }
+
+  subscribeToServerLogs(_callback: (_entry: ServerLogEntry) => void): () => void {
+    // No-op for web - server logs are not available
+    return () => {};
+  }
 }
 
 export const webLifecycle = new WebLifecycle();