refactor(navigation): unify use-case I/O schemas + presenter + feature error map

Per Plan 9 (spec R1-R28):
- getHeader use case: input z.object({}).strict() (R5); output =
  headerSchema parsed at runtime.
- getHeader controller: unknown input + identity presenter.
- New integrations/api/procedures.ts with navigationProcedure
  ([InputParseError → BAD_REQUEST], [HeaderNotFoundError → NOT_FOUND]).
- Router uses navigationProcedure + .input(getHeaderInputSchema).
- src/index.ts: remove headerQuery; export schemas + IUseCase/Controller
  aliases.
- src/ui/index.ts (NEW); package.json adds ./ui subpath.
- R25 + R26 tests added.

Refactor log: §1, §2, §3.1, §3.2, §3.3, §5.1, §5.2, §6.1, §6.2
Spec: R1–R6, R8–R15, R18–R20, R22–R26

packages/navigation/package.json

@@ -5,6 +5,7 @@
   "type": "module",
   "exports": {
     ".": "./src/index.ts",
+    "./ui": "./src/ui/index.ts",
     "./cms": "./src/integrations/cms/index.ts",
     "./api": "./src/integrations/api/router.ts",
     "./di/bind-production": "./src/di/bind-production.ts"

packages/navigation/src/application/use-cases/get-header.use-case.test.ts

@@ -1,4 +1,5 @@
 import { describe, expect, it } from "vitest";
+import { ZodError } from "zod";
 import { getHeaderUseCase } from "@/application/use-cases/get-header.use-case";
 import { MockHeaderRepository } from "@/infrastructure/repositories/header.repository.mock";
 
@@ -6,8 +7,17 @@ describe("getHeaderUseCase", () => {
   it("returns the seeded header items", async () => {
     const repo = new MockHeaderRepository();
     const useCase = getHeaderUseCase(repo);
-    const result = await useCase();
+    const result = await useCase({});
     expect(result.items.length).toBeGreaterThan(0);
     expect(result.items[0]?.label).toBe("Home");
   });
+
+  it("(R25) throws ZodError when repository returns malformed header", async () => {
+    const malformedRepo = {
+      getHeader: async () =>
+        ({ items: [{ label: "", href: "/", external: false }] }) as never,
+    };
+    const useCase = getHeaderUseCase(malformedRepo);
+    await expect(useCase({})).rejects.toBeInstanceOf(ZodError);
+  });
 });

packages/navigation/src/application/use-cases/get-header.use-case.ts

@@ -1,10 +1,27 @@
-import type { Header } from "../../entities/models/header";
+import { z } from "zod";
+
+import { HeaderNotFoundError } from "../../entities/errors/header";
+import { headerSchema } from "../../entities/models/header";
 import type { IHeaderRepository } from "../repositories/header.repository.interface";
 
+// ── Input ────────────────────────────────────────────────────────────────
+export const getHeaderInputSchema = z.object({}).strict();
+export type GetHeaderInput = z.infer<typeof getHeaderInputSchema>;
+
+// ── Output ───────────────────────────────────────────────────────────────
+export const getHeaderOutputSchema = headerSchema;
+export type GetHeaderOutput = z.infer<typeof getHeaderOutputSchema>;
+
+// ── Use case ─────────────────────────────────────────────────────────────
 export type IGetHeaderUseCase = ReturnType<typeof getHeaderUseCase>;
 
 export const getHeaderUseCase =
   (headerRepository: IHeaderRepository) =>
-  async (): Promise<Header> => {
-    return headerRepository.getHeader();
+  // eslint-disable-next-line @typescript-eslint/no-unused-vars
+  async (_input: GetHeaderInput): Promise<GetHeaderOutput> => {
+    const header = await headerRepository.getHeader();
+    if (!header) {
+      throw new HeaderNotFoundError("Header global not found");
+    }
+    return getHeaderOutputSchema.parse(header);
   };

packages/navigation/src/index.ts

@@ -1,3 +1,16 @@
 export type { Header, HeaderItem } from "./entities/models/header";
 export type { NavigationRouter } from "./integrations/api/router";
-export { headerQuery } from "./ui/query";
+export { HeaderNotFoundError } from "./entities/errors/header";
+export { InputParseError } from "./entities/errors/common";
+
+// Use case schemas + types (Plan 9 R18)
+export {
+  getHeaderInputSchema,
+  getHeaderOutputSchema,
+  type GetHeaderInput,
+  type GetHeaderOutput,
+  type IGetHeaderUseCase,
+} from "./application/use-cases/get-header.use-case";
+
+// Controller type aliases
+export type { IGetHeaderController } from "./interface-adapters/controllers/get-header.controller";

packages/navigation/src/integrations/api/procedures.ts

@@ -0,0 +1,12 @@
+import { t } from "@repo/core-shared/trpc/init";
+import { defineErrorMiddleware } from "@repo/core-shared/trpc/define-error-middleware";
+
+import { HeaderNotFoundError } from "../../entities/errors/header";
+import { InputParseError } from "../../entities/errors/common";
+
+export const navigationProcedure = t.procedure.use(
+  defineErrorMiddleware([
+    [InputParseError, "BAD_REQUEST"],
+    [HeaderNotFoundError, "NOT_FOUND"],
+  ]),
+);

packages/navigation/src/integrations/api/router.test.ts

@@ -1,7 +1,23 @@
-import { describe, expect, it } from "vitest";
-import { navigationRouter } from "./router";
+import { afterEach, beforeEach, describe, expect, it } from "vitest";
+import { TRPCError } from "@trpc/server";
+import { injectable } from "inversify";
+import { navigationContainer } from "@/di/container";
+import { NavigationModule } from "@/di/module";
+import { NAVIGATION_SYMBOLS } from "@/di/symbols";
+import { getHeaderUseCase } from "@/application/use-cases/get-header.use-case";
+import { getHeaderController } from "@/interface-adapters/controllers/get-header.controller";
+import { navigationRouter } from "@/integrations/api/router";
 
 describe("navigationRouter", () => {
+  beforeEach(() => {
+    navigationContainer.unbindAll();
+    navigationContainer.load(NavigationModule);
+  });
+
+  afterEach(() => {
+    navigationContainer.unbindAll();
+  });
+
   it("exposes header procedure", () => {
     const names = Object.keys(navigationRouter._def.procedures);
     expect(names).toContain("header");
@@ -9,7 +25,62 @@ describe("navigationRouter", () => {
 
   it("header returns 3 items", async () => {
     const caller = navigationRouter.createCaller({});
-    const result = await caller.header();
+    const result = await caller.header({});
     expect(result.items).toHaveLength(3);
   });
 });
+
+describe("navigationRouter (R26 error mapping)", () => {
+  beforeEach(() => {
+    navigationContainer.unbindAll();
+    navigationContainer.load(NavigationModule);
+  });
+
+  afterEach(() => {
+    navigationContainer.unbindAll();
+  });
+
+  it("translates InputParseError → BAD_REQUEST when extra fields are passed", async () => {
+    const caller = navigationRouter.createCaller({});
+    try {
+      await caller.header({ unexpected: "field" } as unknown as Record<string, never>);
+      throw new Error("expected throw");
+    } catch (e) {
+      expect(e).toBeInstanceOf(TRPCError);
+      expect((e as TRPCError).code).toBe("BAD_REQUEST");
+    }
+  });
+
+  it("translates HeaderNotFoundError → NOT_FOUND when repository returns null", async () => {
+    @injectable()
+    class NullHeaderRepository {
+      async getHeader() {
+        return null as never;
+      }
+    }
+
+    navigationContainer.unbindAll();
+    navigationContainer
+      .bind(NAVIGATION_SYMBOLS.IHeaderRepository)
+      .to(NullHeaderRepository);
+    navigationContainer
+      .bind(NAVIGATION_SYMBOLS.IGetHeaderUseCase)
+      .toDynamicValue((ctx) =>
+        getHeaderUseCase(ctx.container.get(NAVIGATION_SYMBOLS.IHeaderRepository)),
+      );
+    navigationContainer
+      .bind(NAVIGATION_SYMBOLS.IGetHeaderController)
+      .toDynamicValue((ctx) =>
+        getHeaderController(ctx.container.get(NAVIGATION_SYMBOLS.IGetHeaderUseCase)),
+      );
+
+    const caller = navigationRouter.createCaller({});
+    try {
+      await caller.header({});
+      throw new Error("expected throw");
+    } catch (e) {
+      expect(e).toBeInstanceOf(TRPCError);
+      expect((e as TRPCError).code).toBe("NOT_FOUND");
+    }
+  });
+});

packages/navigation/src/integrations/api/router.ts

@@ -1,15 +1,22 @@
-import { router, publicProcedure } from "@repo/core-shared/trpc/init";
+import { router } from "@repo/core-shared/trpc/init";
+
 import { navigationContainer } from "../../di/container";
 import { NAVIGATION_SYMBOLS } from "../../di/symbols";
+
+import { getHeaderInputSchema } from "../../application/use-cases/get-header.use-case";
 import type { IGetHeaderController } from "../../interface-adapters/controllers/get-header.controller";
 
+import { navigationProcedure } from "./procedures";
+
 export const navigationRouter = router({
-  header: publicProcedure.query(() => {
-    const ctrl = navigationContainer.get<IGetHeaderController>(
-      NAVIGATION_SYMBOLS.IGetHeaderController,
-    );
-    return ctrl();
-  }),
+  header: navigationProcedure
+    .input(getHeaderInputSchema)
+    .query(({ input }) => {
+      const ctrl = navigationContainer.get<IGetHeaderController>(
+        NAVIGATION_SYMBOLS.IGetHeaderController,
+      );
+      return ctrl(input);
+    }),
 });
 
 export type NavigationRouter = typeof navigationRouter;

packages/navigation/src/interface-adapters/controllers/get-header.controller.test.ts

@@ -9,7 +9,7 @@ describe("getHeaderController", () => {
     const useCase = getHeaderUseCase(repo);
     const controller = getHeaderController(useCase);
 
-    const result = await controller();
+    const result = await controller({});
 
     expect(result.items.length).toBeGreaterThan(0);
     expect(result.items[0]?.label).toBe("Home");

packages/navigation/src/interface-adapters/controllers/get-header.controller.ts

@@ -1,10 +1,23 @@
-import type { Header } from "../../entities/models/header";
-import type { IGetHeaderUseCase } from "../../application/use-cases/get-header.use-case";
+import { InputParseError } from "../../entities/errors/common";
+import {
+  getHeaderInputSchema,
+  type GetHeaderOutput,
+  type IGetHeaderUseCase,
+} from "../../application/use-cases/get-header.use-case";
+
+function presenter(value: GetHeaderOutput) {
+  return value;
+}
 
 export type IGetHeaderController = ReturnType<typeof getHeaderController>;
 
 export const getHeaderController =
   (getHeaderUseCase: IGetHeaderUseCase) =>
-  async (): Promise<Header> => {
-    return getHeaderUseCase();
+  async (input: unknown): Promise<ReturnType<typeof presenter>> => {
+    const parsed = getHeaderInputSchema.safeParse(input);
+    if (!parsed.success) {
+      throw new InputParseError("Invalid get-header input", { cause: parsed.error });
+    }
+    const result = await getHeaderUseCase(parsed.data);
+    return presenter(result);
   };

packages/navigation/src/ui/index.ts

@@ -0,0 +1 @@
+export { headerQuery } from "./query";