feat(entry): 新增四入口 ViewModel

entry/src/main/ets/viewmodel/PlanViewModel.ets

@@ -0,0 +1,56 @@
+import { PlanRecord, PlanType } from '../model/PlanModels';
+import { PlanRepository } from '../data/repository/PlanRepository';
+import { SessionRepository } from '../data/repository/SessionRepository';
+import { ServiceLocator } from '../di/ServiceLocator';
+
+/**
+ * 计划视图模型：周/月/年类型切换 + 计划数据加载。
+ */
+@ObservedV2
+export class PlanViewModel {
+  @Trace record: PlanRecord = new PlanRecord();
+  @Trace selectedType: string = PlanType.WEEKLY;
+  @Trace loggedIn: boolean = false;
+  @Trace loading: boolean = false;
+  @Trace error: string = '';
+
+  private readonly repository: PlanRepository;
+  private readonly session: SessionRepository;
+
+  constructor(repository: PlanRepository, session: SessionRepository) {
+    this.repository = repository;
+    this.session = session;
+  }
+
+  static create(): PlanViewModel {
+    return new PlanViewModel(
+      ServiceLocator.get('planRepository') as PlanRepository,
+      ServiceLocator.get('sessionRepository') as SessionRepository
+    );
+  }
+
+  async load(): Promise<void> {
+    this.loading = true;
+    this.error = '';
+    this.loggedIn = this.session.isLoggedIn();
+    if (!this.loggedIn) {
+      this.loading = false;
+      return;
+    }
+    try {
+      this.record = await this.repository.observePlan(this.selectedType);
+    } catch (err) {
+      this.error = JSON.stringify(err);
+    } finally {
+      this.loading = false;
+    }
+  }
+
+  async selectType(type: string): Promise<void> {
+    if (this.selectedType === type) {
+      return;
+    }
+    this.selectedType = type;
+    await this.load();
+  }
+}