fix: use Get From List instead of direct list indexing

Direct ${ids}[0] syntax unreliable. Use Get From List ${ids} 0 instead.

tests/robot/api/download.robot

@@ -99,7 +99,7 @@ Remove Item From Queue
     ${add_resp}=    Add To Queue    ${payload}
     ${json}=    Convert String To Json    ${add_resp.text}
     ${ids}=    Get Value From Json    ${json}    $.item_ids
-    ${item_id}=    Set Variable    ${ids}[0]
+    ${item_id}=    Get From List    ${ids}    0
     ${del_resp}=    DELETE API    /api/queue/item/${item_id}
     Response Should Have Status    ${del_resp}    200
 
@@ -115,7 +115,7 @@ Retry Failed Item
     ${add_resp}=    Add To Queue    ${payload}
     ${json}=    Convert String To Json    ${add_resp.text}
     ${ids}=    Get Value From Json    ${json}    $.item_ids
-    ${item_id}=    Set Variable    ${ids}[0]
+    ${item_id}=    Get From List    ${ids}    0
     # Retry endpoint accepts item_ids list, returns 200 even if no items actually failed
     # (retried_count will be 0 if item wasn't in failed state)
     ${retry_payload}=    Create Dictionary    item_ids=${item_id}