feat(task-017): implement git publishing dry-run and commit flow

apps/frontend/tests/article_detail.model.test.mjs

@@ -15,7 +15,7 @@ const compiled = ts.transpileModule(source, {
 const moduleExports = {};
 new Function("exports", compiled.outputText)(moduleExports);
 
-const { buildProductionArtifactRows } = moduleExports;
+const { buildDetailSummary, buildProductionArtifactRows } = moduleExports;
 
 const rows = buildProductionArtifactRows([
   {
@@ -102,3 +102,40 @@ assert.equal(rows[0].status, "SUCCEEDED");
 assert.deepEqual(rows[0].usedEvidenceIds, ["e1", "e2"]);
 assert.equal(rows[1].status, "FAILED");
 assert.deepEqual(rows[1].unsupportedClaims, ["Unverified claim"]);
+
+const detailSummary = buildDetailSummary({
+  article: {
+    id: "a1",
+    target_site_id: "site1",
+    status: "PUBLISH_COMMIT_CREATED",
+    publishing_status: "PUBLISH_COMMIT_CREATED",
+    brief_description: "desc",
+    language: "en",
+    content_type: "longform_guide",
+    created_at: "2026-05-21T00:00:00Z",
+    updated_at: "2026-05-21T00:00:00Z",
+  },
+  target_site: { name: "Demo Site" },
+  workflow_events: [],
+  agent_jobs: [],
+  publish_commit: {
+    id: "pc1",
+    article_id: "a1",
+    target_site_id: "site1",
+    repository_url: "/tmp/repo.git",
+    branch: "main",
+    commit_sha: "abc123",
+    status: "PUBLISH_COMMIT_CREATED",
+    created_at: "2026-05-21T00:00:00Z",
+    content_bundle_manifest: {
+      validation: {
+        label: "Best-effort content-shape validation only.",
+      },
+    },
+  },
+});
+
+assert.equal(
+  detailSummary.publishingValidationLabel,
+  "Best-effort content-shape validation only.",
+);