feat(app): pnpm 一键启动 + Flutter Web 编译修复

1. 新增 pnpm start:dev / pnpm start:stop 命令
   - scripts/dev.mjs: 跨平台启动脚本（后端+管理端+学生端）
   - scripts/stop.mjs: 端口清理停止脚本
   - 根 package.json 定义 pnpm 脚本

2. 修复 Flutter Web 编译（Isar 3.x + flutter_secure_storage 不兼容）
   - isar_database: 条件导出，Web 用空 stub
   - isar_journal_repository: 条件导出，Web 用空 stub
   - sync_engine: 条件导出，Web 用内存队列（无 Isar 持久化）
   - 移除 flutter_secure_storage（v9 web 插件用 dart:html）
   - 新增 SecureTokenStore 接口 + shared_preferences 实现
   - auth_repository 改用 SecureTokenStore 接口

scripts/stop.mjs

@@ -0,0 +1,111 @@
+#!/usr/bin/env node
+/**
+ * 暖记开发环境停止脚本 — 清理所有服务进程
+ *
+ * 用法:
+ *   pnpm start:stop
+ */
+
+import { execSync } from "node:child_process";
+
+const IS_WIN = process.platform === "win32";
+
+// ===== 配置 =====
+const SERVICES = [
+  { port: 3000, name: "后端 (Rust/Axum)" },
+  { port: 5174, name: "管理端前端 (React/Vite)" },
+  { port: 8080, name: "学生端前端 (Flutter Web)" },
+];
+
+// ===== 颜色输出 =====
+const log = {
+  info: (msg) => console.log(`\x1b[34m[INFO]\x1b[0m ${msg}`),
+  ok: (msg) => console.log(`\x1b[32m[OK]\x1b[0m ${msg}`),
+  warn: (msg) => console.log(`\x1b[33m[WARN]\x1b[0m ${msg}`),
+};
+
+// ===== 工具函数 =====
+
+function findPidsOnPort(port) {
+  try {
+    if (IS_WIN) {
+      const out = execSync(
+        `netstat -ano | findstr :${port} | findstr LISTENING`,
+        { encoding: "utf-8", stdio: ["pipe", "pipe", "pipe"] }
+      );
+      return [
+        ...new Set(
+          out
+            .trim()
+            .split("\n")
+            .map((l) => l.trim().split(/\s+/).pop())
+            .filter((p) => p && p !== "0")
+        ),
+      ];
+    }
+    const out = execSync(`lsof -ti :${port}`, {
+      encoding: "utf-8",
+      stdio: ["pipe", "pipe", "pipe"],
+    });
+    return out.trim().split("\n").filter(Boolean);
+  } catch {
+    return [];
+  }
+}
+
+function killPid(pid) {
+  try {
+    if (IS_WIN) {
+      execSync(`taskkill /F /PID ${pid}`, { stdio: "pipe" });
+    } else {
+      execSync(`kill -9 ${pid}`, { stdio: "pipe" });
+    }
+    return true;
+  } catch {
+    return false;
+  }
+}
+
+function killPort(port, name) {
+  const pids = findPidsOnPort(port);
+  if (pids.length === 0) {
+    log.info(`${name} — 端口 ${port} 空闲`);
+    return;
+  }
+  for (const pid of pids) {
+    if (killPid(pid)) {
+      log.ok(`${name} — 已停止 (PID: ${pid}, 端口: ${port})`);
+    } else {
+      log.warn(`${name} — 无法停止 PID: ${pid}`);
+    }
+  }
+}
+
+// ===== 主流程 =====
+
+console.log();
+console.log("\x1b[1m\x1b[36m  ═══ 暖记 — 停止所有服务 ═══\x1b[0m");
+console.log();
+
+log.info("正在停止所有暖记服务...");
+
+for (const { port, name } of SERVICES) {
+  killPort(port, name);
+}
+
+// Windows: 额外清理 erp-server.exe
+if (IS_WIN) {
+  try {
+    execSync("taskkill /F /IM erp-server.exe", { stdio: "pipe" });
+    log.ok("已停止 erp-server.exe");
+  } catch {
+    // 没有运行中的进程，忽略
+  }
+}
+
+// Windows: 清理可能的残留 node 进程（仅清理 pnpm 启动的）
+// 注意：不盲目杀所有 node 进程，只清理端口的即可
+
+console.log();
+log.ok("所有服务已停止");
+console.log();