feat(turbo): turbo gen feature generator (Phase 1, single-entity)

Adds `pnpm turbo gen feature` to scaffold a Lazar-conformant feature
package matching the navigation reference shape: entity + Zod schema,
single use case (`get<Entity>`), controller, mock + Payload-stub real
repository (with span + capture), DI module/container/symbols, and tRPC
router with full BAD_REQUEST/NOT_FOUND error mapping. The generated
`bind-production.ts` and `bind-dev-seed.ts` compose the post-R44
`withSpan(tracer, opts, withCapture(logger, tags, factory(deps)))`
sandwich at bind time.

Verified by generating a sample `packages/example/` feature and running
`pnpm --filter @repo/example lint typecheck test` — all three pass
(9 test files, 25 tests). Cleaned up after verification so no example
package is committed.

Phase-1 limitations (documented in `docs/guides/scaffolding-a-feature.md`
and printed by the generator on success): no Payload CMS templates, no
React Query helpers, faker-driven factories left as stubs, single
entity / single use case, and aggregator wiring (core-api/root,
apps/web-next bindAll) is left as a manual checklist.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

turbo/generators/templates/feature/src/integrations/api/router.test.ts.hbs

@@ -0,0 +1,93 @@
+import { afterEach, beforeEach, describe, expect, it } from "vitest";
+import { TRPCError } from "@trpc/server";
+import { injectable } from "inversify";
+import { {{camelCase name}}Container } from "@/di/container";
+import { {{pascalCase name}}Module } from "@/di/module";
+import { {{constantCase name}}_SYMBOLS } from "@/di/symbols";
+import { get{{pascalCase entity}}UseCase } from "@/application/use-cases/get-{{kebabCase entity}}.use-case";
+import { get{{pascalCase entity}}Controller } from "@/interface-adapters/controllers/get-{{kebabCase entity}}.controller";
+import { {{camelCase name}}Router } from "@/integrations/api/router";
+
+describe("{{camelCase name}}Router", () => {
+  beforeEach(() => {
+    {{camelCase name}}Container.unbindAll();
+    {{camelCase name}}Container.load({{pascalCase name}}Module);
+  });
+
+  afterEach(() => {
+    {{camelCase name}}Container.unbindAll();
+  });
+
+  it("exposes the get{{pascalCase entity}} procedure", () => {
+    const names = Object.keys({{camelCase name}}Router._def.procedures);
+    expect(names).toContain("get{{pascalCase entity}}");
+  });
+
+  it("get{{pascalCase entity}} returns the seeded {{camelCase entity}}", async () => {
+    const caller = {{camelCase name}}Router.createCaller({});
+    const result = await caller.get{{pascalCase entity}}({ id: "seed-1" });
+    expect(result.id).toBe("seed-1");
+  });
+});
+
+describe("{{camelCase name}}Router (error mapping)", () => {
+  beforeEach(() => {
+    {{camelCase name}}Container.unbindAll();
+    {{camelCase name}}Container.load({{pascalCase name}}Module);
+  });
+
+  afterEach(() => {
+    {{camelCase name}}Container.unbindAll();
+  });
+
+  it("translates InputParseError → BAD_REQUEST when extra fields are passed", async () => {
+    const caller = {{camelCase name}}Router.createCaller({});
+    try {
+      await caller.get{{pascalCase entity}}({
+        id: "seed-1",
+        unexpected: "field",
+      } as unknown as { id: string });
+      throw new Error("expected throw");
+    } catch (e) {
+      expect(e).toBeInstanceOf(TRPCError);
+      expect((e as TRPCError).code).toBe("BAD_REQUEST");
+    }
+  });
+
+  it("translates {{pascalCase entity}}NotFoundError → NOT_FOUND when repository returns null", async () => {
+    @injectable()
+    class Null{{pascalCase entity}}Repository {
+      async get{{pascalCase entity}}() {
+        return null;
+      }
+    }
+
+    {{camelCase name}}Container.unbindAll();
+    {{camelCase name}}Container
+      .bind({{constantCase name}}_SYMBOLS.I{{pascalCase entity}}Repository)
+      .to(Null{{pascalCase entity}}Repository);
+    {{camelCase name}}Container
+      .bind({{constantCase name}}_SYMBOLS.IGet{{pascalCase entity}}UseCase)
+      .toDynamicValue((ctx) =>
+        get{{pascalCase entity}}UseCase(
+          ctx.container.get({{constantCase name}}_SYMBOLS.I{{pascalCase entity}}Repository),
+        ),
+      );
+    {{camelCase name}}Container
+      .bind({{constantCase name}}_SYMBOLS.IGet{{pascalCase entity}}Controller)
+      .toDynamicValue((ctx) =>
+        get{{pascalCase entity}}Controller(
+          ctx.container.get({{constantCase name}}_SYMBOLS.IGet{{pascalCase entity}}UseCase),
+        ),
+      );
+
+    const caller = {{camelCase name}}Router.createCaller({});
+    try {
+      await caller.get{{pascalCase entity}}({ id: "anything" });
+      throw new Error("expected throw");
+    } catch (e) {
+      expect(e).toBeInstanceOf(TRPCError);
+      expect((e as TRPCError).code).toBe("NOT_FOUND");
+    }
+  });
+});