fix: validate multipass output paths

extensions/qa-lab/src/multipass.runtime.test.ts

@@ -7,6 +7,15 @@ describe("qa multipass runtime", () => {
     vi.unstubAllEnvs();
   });
 
+  it("rejects output directories outside the mounted repo root", () => {
+    expect(() =>
+      createQaMultipassPlan({
+        repoRoot: process.cwd(),
+        outputDir: "/tmp/qa-out",
+      }),
+    ).toThrow("qa suite --runner multipass requires --output-dir to stay under the repo root");
+  });
+
   it("reuses suite scenario semantics and resolves mounted artifact paths", () => {
     const repoRoot = process.cwd();
     const outputDir = path.join(repoRoot, ".artifacts", "qa-e2e", "multipass-test");

extensions/qa-lab/src/multipass.runtime.ts

@@ -234,7 +234,9 @@ function createQaMultipassOutputDir(repoRoot: string) {
 function resolveGuestMountedPath(repoRoot: string, hostPath: string) {
   const relativePath = path.relative(repoRoot, hostPath);
   if (relativePath.startsWith("..") || path.isAbsolute(relativePath) || relativePath.length === 0) {
-    throw new Error(`unable to resolve Multipass mounted path for ${hostPath}`);
+    throw new Error(
+      `qa suite --runner multipass requires --output-dir to stay under the repo root (${repoRoot}), got ${hostPath}.`,
+    );
   }
   return path.posix.join(MULTIPASS_MOUNTED_REPO_PATH, ...relativePath.split(path.sep));
 }