feat(editor): scaffold editor package

UI-only feature package for the ADR-029 editor rebuild: tsconfig
rootDir '.', vitest jsdom base with '@' alias and honest L0 baseline
thresholds, conformance ESLint active, React 19, @xyflow/react +
zustand wired against the pre-approved 2026-07-12 library traces.
Minimal feature.manifest.ts (empty useCases — no binders; declares
requiredCores runner-protocol + baseline coverage band) so the editor
participates in pnpm conformance without weakening any lint rule.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016j8z4VHjedXDTjEDNg7qHK

packages/editor/src/feature.manifest.test.ts

@@ -0,0 +1,40 @@
+import { describe, it, expect } from "vitest";
+import {
+  DEFAULT_COVERAGE_BANDS,
+  getCoverageBands,
+} from "@repo/core-shared/conformance";
+import { editorManifest } from "@/feature.manifest";
+
+describe("editorManifest", () => {
+  it("declares the editor feature name", () => {
+    expect(editorManifest.name).toBe("editor");
+  });
+
+  it("declares no use cases — the editor is a UI-only feature (ADR-029)", () => {
+    expect(editorManifest.useCases).toEqual({});
+  });
+
+  it("requires the runner-protocol core (render-frame schema source)", () => {
+    expect(editorManifest.requiredCores).toEqual(["runner-protocol"]);
+  });
+
+  it("declares no realtime channels and no jobs", () => {
+    expect(editorManifest.realtimeChannels).toEqual([]);
+    expect(editorManifest.jobs).toEqual([]);
+  });
+
+  it("declares the default baseline coverage band — drift guard against vitest.config.ts, which inherits the same numbers from nodeVitestConfig", () => {
+    expect(editorManifest.coverage.bands.baseline).toEqual(
+      DEFAULT_COVERAGE_BANDS.baseline,
+    );
+  });
+
+  it("resolves layer bands from defaults via getCoverageBands (no layer dirs exist yet)", () => {
+    expect(getCoverageBands(editorManifest)).toEqual({
+      baseline: DEFAULT_COVERAGE_BANDS.baseline,
+      entities: DEFAULT_COVERAGE_BANDS.entities,
+      "use-cases": DEFAULT_COVERAGE_BANDS["use-cases"],
+      controllers: DEFAULT_COVERAGE_BANDS.controllers,
+    });
+  });
+});