feat: unify installation model catalog

backend/test/workspace-v4-migration.test.ts

@@ -0,0 +1,36 @@
+import { expect, test } from "vitest";
+import { migrateWorkspaceV3Yaml, parseWorkspaceYaml } from "../src/workspaces/schema.js";
+
+const legacy = `workspace:
+  schema_version: 3
+  id: abc
+  name: Example
+  language: en
+dwh:
+  engine: postgres
+  database: warehouse
+  schema: public
+  supported_transports: [postgres_direct]
+semantic_index:
+  vector_store: {engine: qdrant, collection: abc, dimensions: 1024, distance: cosine}
+  embedding: {provider: ollama_internal, model: qwen3-embedding:0.6b, dimensions: 1024}
+llm_policy:
+  default: zai/glm-5.3
+  allowed: [zai/glm-5.3]
+`;
+
+test("strict workspace v4 rejects model-bearing v3 descriptors", () => {
+  expect(() => parseWorkspaceYaml(legacy)).toThrow();
+});
+
+test("v3 to v4 migration removes only model/vector policy and bumps the version", () => {
+  const migrated = migrateWorkspaceV3Yaml(legacy);
+  const workspace = parseWorkspaceYaml(migrated);
+
+  expect(workspace.workspace).toMatchObject({ schema_version: 4, id: "abc" });
+  expect(migrated).not.toMatch(/semantic_index|llm_policy/);
+  expect(workspace.dwh).toEqual({
+    engine: "postgres", database: "warehouse", schema: "public",
+    supported_transports: ["postgres_direct"],
+  });
+});