Revert "Leave staging workflow contracts to coordinated update"

This reverts commit 84449e2ef3.

frontend/tests/staging-backend-workflows.test.ts

@@ -189,6 +189,31 @@ test("Gitea quality gate validates before publishing an immutable ACR manifest",
   assert.doesNotMatch(workflow, /(?:^|:)latest$/m);
 });
 
+test("Gitea staging mutation workflows use the available runner and pinned Node tooling", () => {
+  for (const workflow of [read(giteaDeployWorkflow), read(giteaMigrationWorkflow)]) {
+    assert.equal((workflow.match(/runs-on: manman-linux/g) ?? []).length, 1);
+    assert.doesNotMatch(workflow, /runs-on: xiaoxin/);
+    assert.equal((workflow.match(/NODE_TOOL_SOURCE_IMAGE: swr\.cn-north-4\.myhuaweicloud\.com\/ddn-k8s\/docker\.io\/library\/node:22-bookworm-slim@sha256:ef343465b6a14bbdf2ab52f6e100ec0659a792464fcf72c462370d88b3df909c/g) ?? []).length, 1);
+    assert.equal((workflow.match(/NODE_TOOL_IMAGE: node:22-bookworm-slim/g) ?? []).length, 1);
+    assert.match(workflow, /timeout 180 docker pull "\$NODE_TOOL_SOURCE_IMAGE"/);
+    assert.match(workflow, /docker tag "\$NODE_TOOL_SOURCE_IMAGE" "\$NODE_TOOL_IMAGE"/);
+    assert.match(workflow, /cat > "\$tool_dir\/node" <<'EOF'/);
+    assert.match(workflow, /--volume "\$workdir:\$workdir"/);
+    assert.match(workflow, /--workdir "\$workdir"/);
+    assert.match(workflow, /node:22-bookworm-slim "\$\{0##\*\/\}" "\$@"/);
+    assert.match(workflow, />> "\$GITHUB_PATH"/);
+    assert.match(workflow, /node frontend\/scripts\/staging-image-manifest\.mjs/);
+    assert.doesNotMatch(workflow, /packages\+=\((?:nodejs|npm)\)|apt-get install[^\n]*(?:nodejs|npm)/);
+    assert.doesNotMatch(workflow, /(?:--volume|-v)[^\n]*(?:\$HOME\/\.docker|DOCKER_CONFIG)/);
+    assertOrder(workflow, [
+      "Checkout trusted main controller",
+      "Prepare pinned Node tooling",
+      "Download gate-produced",
+      "node frontend/scripts/staging-image-manifest.mjs",
+    ]);
+  }
+});
+
 test("quality gate builds the Python package with its declared backend dependencies", () => {
   const workflow = read(qualityWorkflow);