fix tests: update JSON paths and add WebSocket keyword library

- download.robot: fix total to total_items in queue statistics test
- websocket.robot: add websocket_keywords.py library and use proper keyword
- tasks.md: remove completed task entries

tests/robot/api/websocket.robot

@@ -5,6 +5,8 @@ Documentation       WebSocket API tests for Aniworld.
 Resource            ${CURDIR}/../resources/common.resource
 Resource            ${CURDIR}/../resources/api_keywords.resource
 
+Library             ${CURDIR}/../resources/websocket_keywords.py
+
 Test Setup          Run Keywords
 ...                 Create Anonymous Session
 ...                 AND    Setup Master Password
@@ -20,10 +22,8 @@ Connect To WebSocket
     [Documentation]    Establish a WebSocket connection with a valid JWT token.
     ${token}=    Login And Get Token
     ${ws_url}=    Set Variable    ws://${SERVER_HOST}:${SERVER_PORT}/ws/connect?token=${token}
-    ${result}=    Evaluate    __import__('asyncio').run(__import__('websockets').connect('${ws_url}'))
-    # Note: Full WebSocket testing requires a custom Python keyword library
-    # or using Browser library's Evaluate with inline JavaScript.
-    Pass Execution    WebSocket connection test requires custom keyword library
+    ${result}=    Connect To WebSocket    ${ws_url}
+    Should Contain    ${result}    ${SERVER_HOST}
 
 # ---------------------------------------------------------------------------
 # Placeholder for WebSocket Room Subscription