refactor(frontend): consolidate features & components into single tree

把 components/admin/* 和 components/platform/* 共 11 个文件
移到对应 features/<name>/ 下,components/ 只保留跨特性共享的
common/ 子目录(features/admin/* 之前和 components/admin/* 同名
共存,迫使 features/admin/AdminPages.tsx 出现 barrel,顺带消除了
barrel 副作用 CSS 丢失的隐患)。

新的目录约定:
  - features/<name>/  = 特性模块,所有页面 / Modal / state / hooks
                         / routes 都在内,无 components/<name>/ 并列
  - components/common/ = 仅放 ≥2 个特性共用的 widgets
                         (Icon、Sidebar、Toast、Topbar、WelcomePanel)

改动:
  - 11 文件 git mv (components/{admin,platform}/* → features/*)
  - 8 文件的 Icon 相对路径 '../common/Icon' → '../../components/common/Icon'
  - 2 文件补 admin.css side-effect import(UserManagementPage /
    ProjectManagementPage 之前依赖 AdminPages barrel)
  - 3 文件(引用方)更新 import:SystemAdminPage、DashboardRoute、
    ScriptsPage
  - 删除 features/admin/AdminPages.tsx barrel(无消费者)
  - 删除空目录 components/admin、components/platform

验证:
  - pnpm typecheck 通过
  - pnpm build 通过,CSS 体积 35.11 kB 与重构前一致(无样式增减)
  - routes.ts / routes/platform.tsx 路径未动,route id 不变

踩坑:
  第一轮把 '../common/Icon' 错改成 '../../../components/common/Icon',
  typecheck 报 11 个 Cannot find module。原因:features/admin/ 和
  components/admin/ 都是 depth 2,'../../X' 在两边都解析到 app/X,
  只有 '../X' 才需要多一层。正确改法是 '../../components/common/Icon'。

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

frontend/app/features/admin/AdminPages.tsx

@@ -1,8 +0,0 @@
-import "../../styles/admin.css";
-import "../../styles/dashboard.css";
-import "../../styles/platform.css";
-
-export { DashboardPage } from "../../components/admin/DashboardPage";
-export { UserManagementPage } from "../../components/admin/UserManagementPage";
-export { ProjectManagementPage } from "../../components/admin/ProjectManagementPage";
-export { SystemAdminPage } from "./SystemAdminPage";

frontend/app/features/admin/ProjectManagementPage.tsx

@@ -2,9 +2,11 @@ import { useEffect, useState } from "react";
 
 import { ApiRequestError, type Employee, type Workspace, type WorkspaceMember } from "../../services/api";
 import { useApi, useAuth } from "../../context/AuthContext";
-import Icon from "../common/Icon";
+import Icon from "../../components/common/Icon";
 import { UserMultiSelect } from "./UserMultiSelect";
 
+import "../../styles/admin.css";
+
 const EMPTY_PROJECT_FORM = {
   workspace_code: "",
   workspace_name: "",

frontend/app/features/admin/SystemAdminPage.tsx

@@ -1,8 +1,8 @@
 import { useState } from "react";
 
 import Icon from "../../components/common/Icon";
-import { UserManagementPage } from "../../components/admin/UserManagementPage";
-import { ProjectManagementPage } from "../../components/admin/ProjectManagementPage";
+import { UserManagementPage } from "./UserManagementPage";
+import { ProjectManagementPage } from "./ProjectManagementPage";
 
 import "../../styles/admin.css";
 

frontend/app/features/admin/UserManagementPage.tsx

@@ -4,6 +4,8 @@ import { ApiRequestError, type Employee } from "../../services/api";
 import { useApi, useAuth } from "../../context/AuthContext";
 import Icon from "../../components/common/Icon";
 
+import "../../styles/admin.css";
+
 const EMPTY_FORM = {
   username: "",
   display_name: "",

frontend/app/features/platform/CreateFolderModal.tsx

@@ -1,5 +1,5 @@
 import { type FormEvent } from "react";
-import Icon from "../common/Icon";
+import Icon from "../../components/common/Icon";
 
 type CreateFolderModalProps = {
   open: boolean;

frontend/app/features/platform/CreateScriptModal.tsx

@@ -1,5 +1,5 @@
 import { type FormEvent } from "react";
-import Icon from "../common/Icon";
+import Icon from "../../components/common/Icon";
 import type { ScriptType, Visibility } from "../../services/api";
 
 type NewScriptForm = {

frontend/app/features/platform/DashboardRoute.tsx

@@ -2,7 +2,7 @@ import { useEffect } from "react";
 import { useNavigate } from "react-router";
 
 import { useAuth } from "~/context/AuthContext";
-import { DashboardPage } from "../../components/admin/DashboardPage";
+import { DashboardPage } from "../admin/DashboardPage";
 import { useScriptWorkspaceStore } from "./state/scriptWorkspaceStore";
 
 export default function DashboardRoute() {

frontend/app/features/platform/DataResourceUploadModal.tsx

@@ -1,5 +1,5 @@
 import { type FormEvent } from "react";
-import Icon from "../common/Icon";
+import Icon from "../../components/common/Icon";
 import type { Visibility } from "../../services/api";
 
 type DataResourceUploadModalProps = {

frontend/app/features/platform/PublishModal.tsx

@@ -1,5 +1,5 @@
 import { type FormEvent } from "react";
-import Icon from "../common/Icon";
+import Icon from "../../components/common/Icon";
 import type { ScriptItem, Visibility } from "../../services/api";
 import { scriptIcon } from "../../features/platform/WorkspaceTree";
 

frontend/app/features/platform/ScriptExplorer.tsx

@@ -1,5 +1,5 @@
 import { type ChangeEvent, type MouseEvent as ReactMouseEvent, type RefObject, useMemo } from "react";
-import Icon from "../common/Icon";
+import Icon from "../../components/common/Icon";
 import { WorkspaceTreeGroup } from "~/features/platform/WorkspaceTree";
 import { useScriptWorkspaceStore } from "~/features/platform/state/scriptWorkspaceStore";
 import type { ScriptItem, WorkspaceDirectory } from "~/services/api";

frontend/app/features/platform/ScriptsPage.tsx

@@ -1,14 +1,14 @@
 import { type FormEvent, useEffect, useMemo, useRef } from "react";
 
 import { useAuth } from "../../context/AuthContext";
-import { CreateFolderModal } from "../../components/platform/CreateFolderModal";
-import { CreateScriptModal } from "../../components/platform/CreateScriptModal";
-import { DataResourceUploadModal } from "../../components/platform/DataResourceUploadModal";
+import { CreateFolderModal } from "./CreateFolderModal";
+import { CreateScriptModal } from "./CreateScriptModal";
+import { DataResourceUploadModal } from "./DataResourceUploadModal";
 import Icon from "../../components/common/Icon";
-import { PublishModal } from "../../components/platform/PublishModal";
-import { ScriptExplorer } from "../../components/platform/ScriptExplorer";
-import { TreeContextMenu } from "../../components/platform/TreeContextMenu";
-import { VersionReceiptModal } from "../../components/platform/VersionReceiptModal";
+import { PublishModal } from "./PublishModal";
+import { ScriptExplorer } from "./ScriptExplorer";
+import { TreeContextMenu } from "./TreeContextMenu";
+import { VersionReceiptModal } from "./VersionReceiptModal";
 
 import { getSessionCache, useScriptWorkspaceStore } from "./state/scriptWorkspaceStore";
 import { useUiStore } from "./state/uiStore";

frontend/app/features/platform/TreeContextMenu.tsx

@@ -1,4 +1,4 @@
-import Icon from "../common/Icon";
+import Icon from "../../components/common/Icon";
 import type { ScriptItem, ScriptType } from "../../services/api";
 
 type ContextMenuState = {

frontend/app/features/platform/VersionReceiptModal.tsx

@@ -1,4 +1,4 @@
-import Icon from "../common/Icon";
+import Icon from "../../components/common/Icon";
 import type { StableVersion } from "../../services/api";
 import { copyToClipboard } from "../../lib/clipboard";