refactor: ♻️ 重构文件结构

src/utils/common.ts

@@ -0,0 +1,6 @@
+import dayjs from "dayjs";
+
+/** 将 Date 对象格式化为 'YYYY-MM-DD HH:mm:ss' 字符串 */
+export function formatTime(date: Date): string {
+  return dayjs(date).format("YYYY-MM-DD HH:mm:ss");
+}

src/utils/storage.ts

@@ -0,0 +1,55 @@
+import { load, type Store } from "@tauri-apps/plugin-store";
+
+let storeInstance: Store | null = null;
+
+async function getStore(): Promise<Store> {
+  if (!storeInstance) {
+    storeInstance = await load("config.json", { defaults: {}, autoSave: true });
+  }
+  return storeInstance;
+}
+
+export async function getItem<T = unknown>(key: string): Promise<T | null> {
+  const store = await getStore();
+  const value = await store.get<T>(key);
+  return value ?? null;
+}
+
+export async function setItem<T = unknown>(
+  key: string,
+  value: T,
+): Promise<void> {
+  const store = await getStore();
+  await store.set(key, value);
+}
+
+export async function removeItem(key: string): Promise<void> {
+  const store = await getStore();
+  await store.delete(key);
+}
+
+/**
+ * 从 localStorage 迁移数据到文件存储（仅首次升级时执行）
+ */
+export async function migrateFromLocalStorage(): Promise<boolean> {
+  const store = await getStore();
+  const migrated = await store.get<boolean>("_migrated");
+  if (migrated) return false;
+
+  let hasMigrated = false;
+  for (const key of ["crm_credentials", "crm_config"]) {
+    const raw = localStorage.getItem(key);
+    if (raw) {
+      try {
+        await store.set(key, JSON.parse(raw));
+        localStorage.removeItem(key);
+        hasMigrated = true;
+      } catch {
+        /* ignore invalid JSON */
+      }
+    }
+  }
+
+  await store.set("_migrated", true);
+  return hasMigrated;
+}