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/stores/logStore.ts

@@ -0,0 +1,29 @@
+import { create } from 'zustand';
+import type { ServerLogEntry } from '@/platform/types';
+
+const MAX_LOG_ENTRIES = 2000;
+
+export interface LogEntry extends ServerLogEntry {
+  timestamp: number;
+}
+
+interface LogStore {
+  entries: LogEntry[];
+  addEntry: (entry: ServerLogEntry) => void;
+  clear: () => void;
+}
+
+export const useLogStore = create<LogStore>((set) => ({
+  entries: [],
+  addEntry: (entry) =>
+    set((state) => {
+      const newEntry: LogEntry = { ...entry, timestamp: Date.now() };
+      const entries = [...state.entries, newEntry];
+      // Cap buffer size
+      if (entries.length > MAX_LOG_ENTRIES) {
+        return { entries: entries.slice(entries.length - MAX_LOG_ENTRIES) };
+      }
+      return { entries };
+    }),
+  clear: () => set({ entries: [] }),
+}));