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

Per Plan 9 (spec R1-R28):
- Use cases: input + output schemas (signIn, signUp); input-only for
  signOut (void output). Use case body validates output via
  outputSchema.parse before returning.
- Controllers: receive `unknown`; safeParse with the use-case schema;
  presenter (returning cookie) for signIn/signUp; void return for
  signOut.
- New integrations/api/procedures.ts with authProcedure built via
  defineErrorMiddleware([[InputParseError,"BAD_REQUEST"],
  [AuthenticationError,"UNAUTHORIZED"], [UnauthenticatedError,
  "UNAUTHORIZED"], [UnauthorizedError,"FORBIDDEN"]]).
- Router uses authProcedure + .input(xInputSchema) for every procedure.
- src/index.ts exports schemas + types + IUseCase/IController aliases.
- package.json gains ./ui subpath; src/ui/index.ts placeholder
  (auth has no query builders today).
- New tests: R25 output-validation per use case (signIn, signUp);
  R26 router error-mapping (UNAUTHORIZED on missing user,
  BAD_REQUEST on schema fail).

Refactor log: §1, §2, §3.1, §3.2, §3.3, §5.1, §5.2, §6.1, §6.2
Spec: R1–R6, R8–R15, R18, R19, R22–R26

packages/auth/src/application/use-cases/sign-in.use-case.test.ts

@@ -1,8 +1,9 @@
 import { describe, it, expect } from "vitest";
-import { signInUseCase } from "@/application/use-cases/sign-in.use-case";
+import { signInUseCase, signInOutputSchema } from "@/application/use-cases/sign-in.use-case";
 import { MockUsersRepository } from "@/infrastructure/repositories/users.repository.mock";
 import { MockAuthenticationService } from "@/infrastructure/services/authentication.service.mock";
 import { AuthenticationError } from "@/entities/errors/auth";
+import type { IAuthenticationService } from "@/application/services/authentication.service.interface";
 import { userFactory } from "@/__factories__/user.factory";
 
 describe("signInUseCase", () => {
@@ -45,3 +46,29 @@ describe("signInUseCase", () => {
     ).rejects.toBeInstanceOf(AuthenticationError);
   });
 });
+
+describe("signInUseCase output validation (R25)", () => {
+  it("throws when authenticationService returns a malformed session", async () => {
+    const users = new MockUsersRepository([]);
+    const seed = userFactory.build({ username: "alice" });
+    await users.createUser(seed);
+
+    const auth = {
+      verifyPassword: async () => true,
+      // session missing required fields → should fail signInOutputSchema.parse
+      createSession: async () => ({ session: { id: 123 }, cookie: null }),
+    } as unknown as IAuthenticationService;
+
+    const useCase = signInUseCase(users, auth);
+    await expect(useCase({ username: "alice", password: "x" })).rejects.toThrow(/parse|invalid/i);
+  });
+
+  it("exports an output schema that mirrors the success shape", () => {
+    expect(signInOutputSchema).toBeDefined();
+    const parsed = signInOutputSchema.safeParse({
+      session: { id: "s1", userId: "u1", expiresAt: new Date() },
+      cookie: { name: "session", value: "s1", attributes: {} },
+    });
+    expect(parsed.success).toBe(true);
+  });
+});