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/build-profile.json5

@@ -1,19 +1,47 @@
 {
   "app": {
-    "signingConfigs": [],
     "products": [
       {
         "name": "default",
-        "signingConfig": "default",
-        "compatibleSdkVersion": "6.0.0.48",
-        "compileSdkVersion": "6.0.0.48"
+        "targetSdkVersion": "6.1.0(23)",
+        "compatibleSdkVersion": "6.1.0(23)",
+        "runtimeOS": "HarmonyOS",
+        "buildOption": {
+          "strictMode": {
+            "caseSensitiveCheck": true,
+            "useNormalizedOHMUrl": true
+          }
+        }
+      }
+    ],
+    "buildModeSet": [
+      {
+        "name": "debug"
+      },
+      {
+        "name": "release"
       }
     ]
   },
   "modules": [
     {
       "name": "entry",
-      "srcPath": "./entry"
+      "srcPath": "./entry",
+      "targets": [
+        {
+          "name": "default",
+          "applyToProducts": ["default"]
+        }
+      ]
+    },
+    {
+      "name": "trulymem-core",
+      "srcPath": "./trulymem-core",
+      "targets": [
+        {
+          "name": "default"
+        }
+      ]
     }
   ]
 }