fix: resolve import errors and test failures after segment 4 merge

- Update BaseNodeData import path to dify_graph.entities.base_node_data
- Change NodeType.COMMAND/FILE_UPLOAD to BuiltinNodeTypes constants
- Fix system_oauth_encryption -> system_encryption rename in commands
- Remove tests for deleted agent runner modules
- Fix Avatar: named import + string size API in collaboration files
- Add missing skill feature deps: @monaco-editor/react, react-arborist,
  @tanstack/react-virtual
- Fix frontend test mocks: add useUserProfile, useLeaderRestoreListener,
  next/navigation mock, and nodeOutputVars to expected payload

Made-with: Cursor

web/app/components/workflow/comment/comment-input.tsx

@@ -1,7 +1,7 @@
 import type { FC, PointerEvent as ReactPointerEvent } from 'react'
 import { memo, useCallback, useEffect, useRef, useState } from 'react'
 import { useTranslation } from 'react-i18next'
-import Avatar from '@/app/components/base/avatar'
+import { Avatar } from '@/app/components/base/avatar'
 import { useAppContext } from '@/context/app-context'
 import { cn } from '@/utils/classnames'
 import { MentionInput } from './mention-input'
@@ -153,9 +153,9 @@ export const CommentInput: FC<CommentInputProps> = memo(({
               <div className="flex h-full w-full items-center justify-center">
                 <div className="h-6 w-6 overflow-hidden rounded-full">
                   <Avatar
-                    avatar={userProfile.avatar_url}
+                    avatar={userProfile.avatar_url ?? null}
                     name={userProfile.name}
-                    size={24}
+                    size="sm"
                     className="h-full w-full"
                   />
                 </div>