feat(stats): add stats server, API endpoints, config, and Anki integration

- Hono HTTP server with 20+ REST endpoints for stats data
- Stats overlay BrowserWindow with toggle keybinding
- IPC channel definitions and preload bridge
- Stats config section (toggleKey, serverPort, autoStartServer, autoOpenBrowser)
- Config resolver for stats section
- AnkiConnect proxy endpoints (guiBrowse, notesInfo)
- Note ID passthrough in card mining callback chain
- Stats CLI command with autoOpenBrowser respect

src/preload.ts

@@ -208,6 +208,8 @@ const electronAPI: ElectronAPI = {
     ipcRenderer.invoke(IPC_CHANNELS.request.getKeybindings),
   getConfiguredShortcuts: (): Promise<Required<ShortcutsConfig>> =>
     ipcRenderer.invoke(IPC_CHANNELS.request.getConfigShortcuts),
+  getStatsToggleKey: (): Promise<string> =>
+    ipcRenderer.invoke(IPC_CHANNELS.request.getStatsToggleKey),
   getControllerConfig: (): Promise<ResolvedControllerConfig> =>
     ipcRenderer.invoke(IPC_CHANNELS.request.getControllerConfig),
   saveControllerConfig: (update: ControllerConfigUpdate): Promise<void> =>
@@ -236,6 +238,10 @@ const electronAPI: ElectronAPI = {
     ipcRenderer.send(IPC_CHANNELS.command.toggleOverlay);
   },
 
+  toggleStatsOverlay: () => {
+    ipcRenderer.send(IPC_CHANNELS.command.toggleStatsOverlay);
+  },
+
   getAnkiConnectStatus: (): Promise<boolean> =>
     ipcRenderer.invoke(IPC_CHANNELS.request.getAnkiConnectStatus),
   setAnkiConnectEnabled: (enabled: boolean) => {