diff --git a/.github/workflows/skillsync.yml b/.github/workflows/skillsync.yml
index 83b7908..c22c060 100644
--- a/.github/workflows/skillsync.yml
+++ b/.github/workflows/skillsync.yml
@@ -10,6 +10,7 @@ on:
       - ".claude/skills/**"
       - ".cursor/skills/**"
       - "src/**"
+      - "browser/**"
       - "desktop/**"
       - "scripts/**"
       - "tests/**"
@@ -55,6 +56,7 @@ jobs:
       - run: npm test
       - run: npm test -- --run tests/integration/product-trust-loop.test.ts tests/integration/live-runtime-preparation.test.ts tests/docs/documentation.test.ts
       - run: npm run type-check
+      - run: npm run build:browser
       - run: npm run lint
       - run: npm pack --dry-run
       - name: Generate SBOM preview (non-blocking)
diff --git a/browser/main.ts b/browser/main.ts
index 0113c82..e914ba8 100644
--- a/browser/main.ts
+++ b/browser/main.ts
@@ -54,4 +54,9 @@ function check() {
 input.value = example;
 input.addEventListener("input",clear);
 document.querySelector("#check")!.addEventListener("click",check);
-document.querySelector("#example")!.addEventListener("click",()=>{input.value=example;clear();input.focus()});
+document.querySelector("#example")!.addEventListener("click", () => {
+  if (input.value.trim() && input.value !== example && !window.confirm("用示例替换当前文档？")) return;
+  input.value = example;
+  clear();
+  input.focus();
+});
diff --git a/browser/tsconfig.json b/browser/tsconfig.json
new file mode 100644
index 0000000..13a8347
--- /dev/null
+++ b/browser/tsconfig.json
@@ -0,0 +1,12 @@
+{
+  "extends": "../tsconfig.json",
+  "compilerOptions": {
+    "rootDir": "..",
+    "lib": ["ES2022", "DOM"],
+    "types": [],
+    "module": "ESNext",
+    "moduleResolution": "Bundler",
+    "noEmit": true
+  },
+  "include": ["main.ts"]
+}
diff --git a/package.json b/package.json
index 3394369..2ee9488 100644
--- a/package.json
+++ b/package.json
@@ -54,7 +54,7 @@
     "check": "npm test && npm run type-check && npm run lint && npm run build",
     "prepack": "npm run build",
     "pretest": "npm run build",
-    "build:browser": "vite build browser --base ./ --outDir ../browser-dist --emptyOutDir"
+    "build:browser": "tsc -p browser/tsconfig.json && vite build browser --base ./ --outDir ../browser-dist --emptyOutDir"
   },
   "dependencies": {
     "commander": "^13.1.0",
diff --git a/tests/cli/test.test.ts b/tests/cli/test.test.ts
index cda3f1c..2f0e706 100644
--- a/tests/cli/test.test.ts
+++ b/tests/cli/test.test.ts
@@ -2,7 +2,8 @@ import { mkdir, mkdtemp, writeFile } from "node:fs/promises";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
 
-import { describe, expect, it } from "vitest";
+import { describe, expect, it, vi } from "vitest";
+import { SpawnCommandRunner } from "../../src/sandbox/command";
 
 import { runCli } from "../../src/cli/index";
 import { publicAvailabilityFinding } from "../../src/cli/commands/test-v2";
@@ -320,20 +321,30 @@ describe("skillsync test", () => {
   it("blocks Docker explicitly without fallback", async () => {
     const root = await mkdtemp(join(tmpdir(), "skillsync-behavior-v2-docker-"));
     const fixtureRoot = await createV2Fixture(root, "docker");
-    const result = await runCli([
-      "test",
-      "--fixture",
-      fixtureRoot,
-      "--execute",
-      "--backend",
-      "docker",
-      "--format",
-      "json",
-    ]);
-
-    expect(result.exitCode).toBe(4);
-    expect(result.stdout).toMatch(/sandbox\.backend-unavailable/);
-    expect(JSON.parse(result.stdout).execution.status).toBe("blocked");
+    const hostCommand = vi.spyOn(SpawnCommandRunner.prototype, "run").mockResolvedValue({
+      exitCode: null, stdout: "", stderr: "", timedOut: true, outputLimitExceeded: false,
+    });
+    try {
+      const result = await runCli([
+        "test",
+        "--fixture",
+        fixtureRoot,
+        "--execute",
+        "--backend",
+        "docker",
+        "--format",
+        "json",
+      ]);
+
+      expect(result.exitCode).toBe(4);
+      expect(result.stdout).toMatch(/sandbox\.backend-unavailable/);
+      expect(JSON.parse(result.stdout).execution.status).toBe("blocked");
+      expect(hostCommand.mock.calls.map(([spec]) => [spec.executable, ...spec.args])).toEqual([
+        ["docker", "version", "--format", "{{.Server.Version}}"],
+      ]);
+    } finally {
+      hostCommand.mockRestore();
+    }
   });
 
   it("returns code 2 for an invalid v2 manifest", async () => {