chore: 初始化 BlockFlow Workbench 仓库

建立前端与 Tauri 桌面端的首个版本提交，包含核心编辑器、项目文件读写、测试与构建配置。

补充 Git 忽略规则和换行规范，排除依赖、构建产物、本地运行日志与临时验证文件，方便在其他电脑继续开发。

tests/expression.test.ts

@@ -0,0 +1,79 @@
+import { describe, expect, it } from "vitest"
+import { evaluateExpression, resolvePath } from "../src/core/expression"
+import type { ScopeFrame } from "../src/core/expression"
+
+const scopes: ScopeFrame[] = [
+  {
+    type: "data",
+    values: {
+      user: {
+        name: "张三",
+        level: 4,
+        type: "developer",
+        isVip: true
+      },
+      tags: ["important", "draft"],
+      items: [
+        { title: "A", price: 1 },
+        { title: "B", price: 2 }
+      ],
+      disabled: false
+    }
+  }
+]
+
+describe("expression evaluator", () => {
+  it("resolves nested paths and array access", () => {
+    expect(resolvePath("user.name", scopes)).toMatchObject({
+      found: true,
+      value: "张三"
+    })
+    expect(resolvePath("items[0].title", scopes)).toMatchObject({
+      found: true,
+      value: "A"
+    })
+  })
+
+  it("evaluates comparisons", () => {
+    expect(evaluateExpression("user.level >= 3", scopes)).toMatchObject({
+      ok: true,
+      value: true
+    })
+    expect(evaluateExpression("user.type == \"developer\"", scopes)).toMatchObject({
+      ok: true,
+      value: true
+    })
+  })
+
+  it("evaluates logical operators", () => {
+    expect(evaluateExpression("user.isVip && user.level >= 3", scopes)).toMatchObject({
+      ok: true,
+      value: true
+    })
+    expect(evaluateExpression("!disabled", scopes)).toMatchObject({
+      ok: true,
+      value: true
+    })
+  })
+
+  it("evaluates contains", () => {
+    expect(evaluateExpression("tags contains \"important\"", scopes)).toMatchObject({
+      ok: true,
+      value: true
+    })
+  })
+
+  it("evaluates length access", () => {
+    expect(evaluateExpression("items.length > 0", scopes)).toMatchObject({
+      ok: true,
+      value: true
+    })
+  })
+
+  it("evaluates nullish fallback", () => {
+    expect(evaluateExpression("missing.name ?? \"未命名\"", scopes)).toMatchObject({
+      ok: true,
+      value: "未命名"
+    })
+  })
+})