feat: add file logging toggle and logout confirmation

File logging defaulted to always-on meant the log grew silently on every
run with no way to turn it off. Changing the default to error-only and
exposing the toggle in Settings lets users opt in only when debugging.

The logout button previously triggered immediately without warning, making
accidental logouts unrecoverable without re-running the device code flow.
A confirmation step (Ja/Nein, gamepad-navigable) prevents that.

src/main/index.ts

@@ -9,7 +9,7 @@ import { getHlsCacheEnabled } from './prefs/hlsCachePref'
 import log from 'electron-log/main'
 
 log.initialize()
-log.transports.file.level = 'info'
+log.transports.file.level = 'error'
 log.transports.console.level = 'debug'
 
 const isDev = !app.isPackaged

src/main/ipc/channels.ts

@@ -30,6 +30,7 @@ export const IPC = {
   appGetCacheSize: 'app:get-cache-size',
   appClearCache: 'app:clear-cache',
   appSetHlsCacheEnabled: 'app:set-hls-cache-enabled',
+  appSetFileLoggingEnabled: 'app:set-file-logging-enabled',
 
   /** main → renderer */
   gamepadInput: 'gamepad-input'

src/main/ipc/handlers.ts

@@ -37,6 +37,9 @@ export function registerIpcHandlers(
   safeHandle(IPC.appSetHlsCacheEnabled, (enabled: boolean) => {
     setHlsCacheEnabled(Boolean(enabled))
   })
+  safeHandle(IPC.appSetFileLoggingEnabled, (enabled: boolean) => {
+    log.transports.file.level = Boolean(enabled) ? 'info' : 'error'
+  })
 
   safeHandle(IPC.authStatus, () => auth.getStatus())
   safeHandle(IPC.authConfigured, () => auth.isConfigured())