feat: add scoped assets and storage core

tests/assets-contract.test.ts

@@ -0,0 +1,48 @@
+import { readFile } from "node:fs/promises";
+import { describe, expect, it } from "vitest";
+import type { Asset } from "@/lib/types";
+
+type AssetsContract = {
+  version: number;
+  asset: Asset;
+  defaults: {
+    platformExternalName: string;
+    publicExternalName: string;
+    platformExternalTags: string[];
+    publicRequiredTags: string[];
+    platformRegisteredFrom: string;
+    publicRegisteredFrom: string;
+  };
+  publicVisibility: { jobLookupLimit: number; clientTagPrefix: string };
+};
+
+describe("assets v1 compatibility contract", () => {
+  it("freezes the TypeScript wire shape, defaults, and public visibility rule", async () => {
+    const contract = JSON.parse(await readFile(new URL("../contracts/assets/assets-v1.json", import.meta.url), "utf8")) as AssetsContract;
+    const asset: Asset = contract.asset;
+
+    expect(contract.version).toBe(1);
+    expect(asset).toEqual({
+      id: "asset-contract-1",
+      ownerId: "owner-1",
+      kind: "image",
+      name: "poster.png",
+      url: "https://cdn.example.test/uploads/poster.png",
+      storagePath: "uploads/2026-08-13/poster.png",
+      source: "upload",
+      tags: ["upload"],
+      metadata: { contentType: "image/png", size: 4 },
+      createdAt: "2026-08-13T08:00:00.000Z",
+      updatedAt: "2026-08-13T08:00:00.000Z"
+    });
+    expect(contract.defaults).toEqual({
+      platformExternalName: "外部图片",
+      publicExternalName: "外部素材",
+      platformExternalTags: ["external"],
+      publicRequiredTags: ["external", "public-api", "api-client:agent-a"],
+      platformRegisteredFrom: "api",
+      publicRegisteredFrom: "public-api"
+    });
+    expect(contract.publicVisibility).toEqual({ jobLookupLimit: 200, clientTagPrefix: "api-client:" });
+  });
+});