fix: prevent EventEmitter memory leak in useApiServer hook (#11385)

Implement single instance IPC subscription pattern to resolve MaxListenersExceededWarning. Previously, each component using useApiServer would register a separate 'api-server:ready' listener, and React strict mode double rendering would quickly exceed the 10 listener limit.

Changes:
- Add module-level subscription manager with onReadyCallbacks Set
- Ensure only one IPC listener is registered regardless of component count
- Use useRef to maintain stable callback references
- Properly cleanup subscriptions when all components unmount

This maintains existing behavior while keeping listener count constant at 1.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude <noreply@anthropic.com>

src/renderer/src/hooks/useApiServer.ts

@@ -1,11 +1,31 @@
 import { loggerService } from '@logger'
 import { useAppDispatch, useAppSelector } from '@renderer/store'
 import { setApiServerEnabled as setApiServerEnabledAction } from '@renderer/store/settings'
-import { useCallback, useEffect, useState } from 'react'
+import { useCallback, useEffect, useRef, useState } from 'react'
 import { useTranslation } from 'react-i18next'
 
 const logger = loggerService.withContext('useApiServer')
 
+// Module-level single instance subscription to prevent EventEmitter memory leak
+// Only one IPC listener will be registered regardless of how many components use this hook
+const onReadyCallbacks = new Set<() => void>()
+let removeIpcListener: (() => void) | null = null
+
+const ensureIpcSubscribed = () => {
+  if (!removeIpcListener) {
+    removeIpcListener = window.api.apiServer.onReady(() => {
+      onReadyCallbacks.forEach((cb) => cb())
+    })
+  }
+}
+
+const cleanupIpcIfEmpty = () => {
+  if (onReadyCallbacks.size === 0 && removeIpcListener) {
+    removeIpcListener()
+    removeIpcListener = null
+  }
+}
+
 export const useApiServer = () => {
   const { t } = useTranslation()
   // FIXME: We currently store two copies of the config data in both the renderer and the main processes,
@@ -102,15 +122,28 @@ export const useApiServer = () => {
     checkApiServerStatus()
   }, [checkApiServerStatus])
 
-  // Listen for API server ready event
+  // Use ref to keep the latest checkApiServerStatus without causing re-subscription
+  const checkStatusRef = useRef(checkApiServerStatus)
   useEffect(() => {
-    const cleanup = window.api.apiServer.onReady(() => {
-      logger.info('API server ready event received, checking status')
-      checkApiServerStatus()
+    checkStatusRef.current = checkApiServerStatus
   })
 
-    return cleanup
-  }, [checkApiServerStatus])
+  // Create stable callback for the single instance subscription
+  const handleReady = useCallback(() => {
+    logger.info('API server ready event received, checking status')
+    checkStatusRef.current()
+  }, [])
+
+  // Listen for API server ready event using single instance subscription
+  useEffect(() => {
+    ensureIpcSubscribed()
+    onReadyCallbacks.add(handleReady)
+
+    return () => {
+      onReadyCallbacks.delete(handleReady)
+      cleanupIpcIfEmpty()
+    }
+  }, [handleReady])
 
   return {
     apiServerConfig,