feat(logger): sync renderer log level cache and support verbose IPC

- Add LOGGER_LEVEL_CHANGED IPC channel for broadcasting level changes
- setLogLevel() now notifies all BrowserWindows when level changes
- Add verbose case in IPC forwardToWinston (was falling through to info)
- Renderer logger API listens for level changes and updates cached level
- Add cleanup() method to remove level change listener

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/shared/ipc-channels.ts

@@ -93,6 +93,7 @@ export const IPC_CHANNELS = {
   // Logger
   LOGGER_FORWARD: 'logger:forward',
   LOGGER_GET_LEVEL: 'logger:getLevel',
+  LOGGER_LEVEL_CHANGED: 'logger:levelChanged',
 
   // Report
   REPORT_LIST_ALL: 'report:listAll',