refactor: split Marketplace, Server, Home, AppDetails views; minor frontend quality fixes

- F29-F32: Split 4 views (Marketplace 1293→505, Server 1132→486, Home 1059→394, AppDetails 1036→386)
- F20: Add aria-current="page" to Dashboard nav links
- F21: Add 150ms search debounce in Marketplace and Apps views
- F22: Reduce backdrop-filter blur to 8px on mobile for GPU performance
- F23: Track and clear WebSocket connect check interval in all paths

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

neode-ui/src/api/websocket.ts

@@ -29,6 +29,7 @@ export class WebSocketClient {
   private _state: ConnectionState = 'disconnected'
   private isReconnecting = false
   private parseErrorCount = 0
+  private connectCheckInterval: ReturnType<typeof setInterval> | null = null
 
   constructor(url: string = '/ws/db') {
     this.url = url
@@ -81,25 +82,26 @@ export class WebSocketClient {
       // If connecting, wait for it
       if (this.ws && this.ws.readyState === WebSocket.CONNECTING) {
         if (import.meta.env.DEV) console.log('[WebSocket] Already connecting, waiting...')
-        const checkInterval = setInterval(() => {
+        this.clearConnectCheck()
+        this.connectCheckInterval = setInterval(() => {
           if (this.ws) {
             if (this.ws.readyState === WebSocket.OPEN) {
-              clearInterval(checkInterval)
+              this.clearConnectCheck()
               resolve()
             } else if (this.ws.readyState === WebSocket.CLOSED || this.ws.readyState === WebSocket.CLOSING) {
-              clearInterval(checkInterval)
+              this.clearConnectCheck()
               // Connection failed or closing, will be handled by onclose
               reject(new Error('Connection closed during connect'))
             }
           } else {
-            clearInterval(checkInterval)
+            this.clearConnectCheck()
             reject(new Error('WebSocket was cleared'))
           }
         }, 100)
-        
+
         // Timeout after 5 seconds
         setTimeout(() => {
-          clearInterval(checkInterval)
+          this.clearConnectCheck()
           if (this.ws && this.ws.readyState !== WebSocket.OPEN) {
             reject(new Error('Connection timeout'))
           }
@@ -285,6 +287,13 @@ export class WebSocketClient {
     this.connectionStateCallbacks.forEach((callback) => callback(state))
   }
 
+  private clearConnectCheck(): void {
+    if (this.connectCheckInterval) {
+      clearInterval(this.connectCheckInterval)
+      this.connectCheckInterval = null
+    }
+  }
+
   private startHeartbeat(): void {
     this.stopHeartbeat()
 
@@ -334,7 +343,8 @@ export class WebSocketClient {
     this.reconnectAttempts = 0
     this.setConnectionState('disconnecting')
     this.stopHeartbeat()
-    
+    this.clearConnectCheck()
+
     // Clear reconnect timer
     if (this.reconnectTimer) {
       clearTimeout(this.reconnectTimer)