refactor: 按 sample_in_harmonyos 多层模块化架构重构工程结构

- 新增 common/ 公共模块：模型、服务、组件、常量
- 新增 features/ 功能模块：graph(星图)、chat(聊天)、settings(设置)、commonbusiness
- 新增 products/phone 产品入口层：EntryAbility + Index + MainPage
- Index.ets 简化为纯路由入口，TabNavigation 移至 MainPage 统一管理
- 更新 build-profile.json5 注册所有新模块
- 迁移原始 entry/ 代码到分层架构，保持功能完整

features/settings/Index.ets

@@ -0,0 +1 @@
+export { SettingsPage } from './src/main/ets/pages/SettingsPage';

features/settings/build-profile.json5

@@ -0,0 +1,8 @@
+{
+  "apiType": "stageMode",
+  "targets": [
+    {
+      "name": "default"
+    }
+  ]
+}

features/settings/oh-package.json5

@@ -0,0 +1,11 @@
+{
+  "name": "@ohos/settings",
+  "version": "1.0.0",
+  "description": "TrulyMEM settings feature module",
+  "main": "Index.ets",
+  "author": "",
+  "license": "",
+  "dependencies": {
+    "@ohos/common": "file:../../common"
+  }
+}

features/settings/src/main/ets/pages/SettingsPage.ets

@@ -0,0 +1,126 @@
+import dataPreferences from '@ohos.data.preferences';
+
+@Component
+export struct SettingsPage {
+    @State baseUrl: string = '';
+    @State model: string = '';
+    @State apiKey: string = '';
+    private pref?: dataPreferences.Preferences;
+
+    async aboutToAppear() {
+        const ctx = getContext(this);
+        this.pref = await dataPreferences.getPreferences(ctx, 'trulymem_config');
+        this.baseUrl = String(await this.pref.get('base_url', 'https://api.deepseek.com'));
+        this.model = String(await this.pref.get('model', 'deepseek-chat'));
+        this.apiKey = String(await this.pref.get('api_key', ''));
+    }
+
+    async onBaseUrlChange(value: string) {
+        this.baseUrl = value;
+        await this.pref?.put('base_url', value);
+        await this.pref?.flush();
+    }
+
+    async onModelChange(value: string) {
+        this.model = value;
+        await this.pref?.put('model', value);
+        await this.pref?.flush();
+    }
+
+    async onApiKeyChange(value: string) {
+        this.apiKey = value;
+        await this.pref?.put('api_key', value);
+        await this.pref?.flush();
+    }
+
+    build() {
+        Stack() {
+            // 主题色光晕背景
+            Column()
+                .width(200)
+                .height(200)
+                .backgroundColor('rgba(124,77,255,0.15)')
+                .blur(40)
+                .borderRadius(100)
+                .position({ x: '10%', y: '20%' })
+
+            Column() {
+                Text('API 配置')
+                    .fontSize(24)
+                    .fontWeight(FontWeight.Bold)
+                    .fontColor('#FFFFFF')
+                    .margin({ top: 20, bottom: 16 })
+
+                // Base URL 设置项
+                Column() {
+                    Text('Base URL')
+                        .fontSize(14)
+                        .fontColor('#FFFFFF')
+                        .width('100%')
+                        .margin({ bottom: 8 })
+
+                    TextInput({ placeholder: 'https://api.deepseek.com', text: this.baseUrl })
+                        .onChange((v: string) => { this.onBaseUrlChange(v); })
+                        .backgroundColor('rgba(255,255,255,0.1)')
+                        .borderRadius(8)
+                        .border({ width: 1, color: 'rgba(124,77,255,0.3)' })
+                        .height(40)
+                }
+                .padding(12)
+                .backgroundColor('rgba(255,255,255,0.05)')
+                .borderRadius(12)
+                .backgroundBlurStyle(BlurStyle.Thin)
+                .margin({ bottom: 12 })
+
+                // Model ID 设置项
+                Column() {
+                    Text('Model ID')
+                        .fontSize(14)
+                        .fontColor('#FFFFFF')
+                        .width('100%')
+                        .margin({ bottom: 8 })
+
+                    TextInput({ placeholder: 'deepseek-chat', text: this.model })
+                        .onChange((v: string) => { this.onModelChange(v); })
+                        .backgroundColor('rgba(255,255,255,0.1)')
+                        .borderRadius(8)
+                        .border({ width: 1, color: 'rgba(124,77,255,0.3)' })
+                        .height(40)
+                }
+                .padding(12)
+                .backgroundColor('rgba(255,255,255,0.05)')
+                .borderRadius(12)
+                .backgroundBlurStyle(BlurStyle.Thin)
+                .margin({ bottom: 12 })
+
+                // API Key 设置项
+                Column() {
+                    Text('API Key')
+                        .fontSize(14)
+                        .fontColor('#FFFFFF')
+                        .width('100%')
+                        .margin({ bottom: 8 })
+
+                    TextInput({ placeholder: 'sk-...', text: this.apiKey })
+                        .type(InputType.Password)
+                        .onChange((v: string) => { this.onApiKeyChange(v); })
+                        .backgroundColor('rgba(255,255,255,0.1)')
+                        .borderRadius(8)
+                        .border({ width: 1, color: 'rgba(124,77,255,0.3)' })
+                        .height(40)
+                }
+                .padding(12)
+                .backgroundColor('rgba(255,255,255,0.05)')
+                .borderRadius(12)
+                .backgroundBlurStyle(BlurStyle.Thin)
+                .margin({ bottom: 12 })
+            }
+            .padding(16)
+            .width('100%')
+        }
+        .width('100%')
+        .height('100%')
+        .backgroundColor('rgba(26,27,46,0.95)')
+        .backgroundBlurStyle(BlurStyle.Regular)
+    }
+}