feat: 纯血鸿蒙 ArkTS 工程（harmonyos 分支）

- 新增 harmonyos/ 目录：完整 ArkTS 项目
  - GraphDatabase.ets：@ohos.data.relationalStore 图数据库
  - Index.ets：Tabs 导航（星图|聊天|设置）
  - GraphPage.ets：WebView 星图（Three.js 3D）
  - ChatPage.ets：聊天 + HTTP AI API 调用
  - SettingsPage.ets：@ohos.data.preferences 配置
  - graph.html：Three.js 力导向星图可视化
- 删除：ui/ TUI 代码、core/migrate.py 多用户迁移、trulymem_entry.py
- 配置：build-profile.json5, module.json5, permissions

harmonyos/entry/src/main/module.json5

@@ -0,0 +1,38 @@
+{
+  "module": {
+    "name": "entry",
+    "type": "entry",
+    "description": "$string:module_desc",
+    "mainElement": "EntryAbility",
+    "deviceTypes": ["phone", "tablet", "2in1"],
+    "deliveryWithInstall": true,
+    "installationFree": false,
+    "pages": "$profile:main_pages",
+    "abilities": [
+      {
+        "name": "EntryAbility",
+        "srcEntry": "./ets/entryability/EntryAbility.ets",
+        "description": "$string:EntryAbility_desc",
+        "icon": "$media:layered_image",
+        "label": "$string:EntryAbility_label",
+        "startWindowIcon": "$media:startIcon",
+        "startWindowBackground": "$color:start_window_background",
+        "exported": true,
+        "skills": [
+          {
+            "entities": ["entity.system.home"],
+            "actions": ["action.system.home"]
+          }
+        ]
+      }
+    ],
+    "requestPermissions": [
+      {
+        "name": "ohos.permission.INTERNET"
+      },
+      {
+        "name": "ohos.permission.GET_NETWORK_INFO"
+      }
+    ]
+  }
+}