chore(template): clean-slate template snapshot from bb4a0c7

Curated, product-agnostic snapshot of the post-story-04 tree: demo
content deleted, auth-only reference feature, web-next shell, all gates
green. Product-specific docs, ADRs 027-029, PRDs/epics/archive, editor
library traces, and product naming are curated out; generic template
repairs (coverage provider devDeps, root test:coverage script, live
lint fixes, root-only release-please) are kept. See TEMPLATE.md for
provenance, curation list, and usage.

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

packages/core-eslint/rules/atomic-tier-import-direction.test.js

@@ -0,0 +1,74 @@
+import { describe, it } from "vitest";
+import { RuleTester } from "eslint";
+import rule from "./atomic-tier-import-direction.js";
+
+const tester = new RuleTester({
+  languageOptions: {
+    parser: await import("@typescript-eslint/parser"),
+    ecmaVersion: "latest",
+    sourceType: "module",
+    parserOptions: { ecmaFeatures: { jsx: true } },
+  },
+});
+
+describe("atomic-tier-import-direction", () => {
+  it("passes when an organism imports from atoms", () => {
+    tester.run("atomic-tier-import-direction", rule, {
+      valid: [
+        {
+          filename: "/repo/packages/core-ui/src/organisms/Card/Card.tsx",
+          code: `import { Button } from "../../atoms/Button/Button";`,
+        },
+      ],
+      invalid: [],
+    });
+  });
+
+  it("fires when an atom imports from organisms", () => {
+    tester.run("atomic-tier-import-direction", rule, {
+      valid: [],
+      invalid: [
+        {
+          filename: "/repo/packages/core-ui/src/atoms/Button/Button.tsx",
+          code: `import { Card } from "../../organisms/Card/Card";`,
+          errors: [
+            {
+              messageId: "wrongDirection",
+              data: {
+                fromTier: "atoms",
+                toTier: "organisms",
+                importPath: "../../organisms/Card/Card",
+              },
+            },
+          ],
+        },
+      ],
+    });
+  });
+
+  it("is a no-op for files outside any tier folder", () => {
+    tester.run("atomic-tier-import-direction", rule, {
+      valid: [
+        {
+          filename:
+            "/repo/packages/auth/src/application/use-cases/sign-in.use-case.ts",
+          code: `export const x = 1;`,
+        },
+      ],
+      invalid: [],
+    });
+  });
+
+  it("passes for same-tier imports", () => {
+    tester.run("atomic-tier-import-direction", rule, {
+      valid: [
+        {
+          filename:
+            "/repo/packages/core-ui/src/molecules/SearchBar/SearchBar.tsx",
+          code: `import { FormField } from "../FormField/FormField";`,
+        },
+      ],
+      invalid: [],
+    });
+  });
+});