feat: 合并星图和聊天页面为 MainPage，响应式 GridRow 布局

- 新建 MainPage.ets，用 GridRow 响应式布局组合星图+聊天
- Index.ets 改为 2 Tab（TrulyMEM + 设置）
- GraphPage/ChatPage 接收 @Prop db 从父组件传入
- 恢复 README.md / README_EN.md 的特别鸣谢部分

harmonyos/entry/oh-package-lock.json5

@@ -0,0 +1,19 @@
+{
+  "meta": {
+    "stableOrder": true,
+    "enableUnifiedLockfile": false
+  },
+  "lockfileVersion": 3,
+  "ATTENTION": "THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.",
+  "specifiers": {
+    "librcon@../librcon": "librcon@../librcon"
+  },
+  "packages": {
+    "librcon@../librcon": {
+      "name": "librcon",
+      "version": "1.0.0",
+      "resolved": "../librcon",
+      "registryType": "local"
+    }
+  }
+}