Add comprehensive tests for profile-redirect and auth features

19 new tests across 5 test files covering the protected layout redirect,
account page load, registration action (documenting the redirect bug),
and login/register component rendering. Includes shared test utilities.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/lib/test-utils.ts

@@ -0,0 +1,56 @@
+/**
+ * Shared mock data factories for tests.
+ *
+ * NOTE: `vi.mock()` calls must live in each test file (hoisting requirement).
+ * These helpers only build data objects — no mocking side-effects.
+ */
+
+/** Build a minimal `App.Locals` object. Pass a user to simulate an authenticated request. */
+export function createLocals(user?: { id: string; name: string; email: string }): App.Locals {
+	return {
+		session: user
+			? ({
+					id: 'session-1',
+					userId: user.id,
+					expiresAt: new Date(Date.now() + 86_400_000)
+				} as App.Locals['session'])
+			: (undefined as unknown as App.Locals['session']),
+		user: user as unknown as App.Locals['user']
+	};
+}
+
+/** Build a `Request` whose `.formData()` resolves to the given key/value pairs. */
+export function createFormRequest(fields: Record<string, string>): Request {
+	const fd = new FormData();
+	for (const [k, v] of Object.entries(fields)) fd.append(k, v);
+	return new Request('http://localhost', { method: 'POST', body: fd });
+}
+
+/** Minimal user object with sensible defaults. */
+export function mockUser(overrides?: Record<string, unknown>) {
+	return {
+		id: 'user-1',
+		name: 'Jane Doe',
+		email: 'jane@example.com',
+		emailVerified: true,
+		image: null,
+		createdAt: new Date(),
+		updatedAt: new Date(),
+		roleId: null,
+		...overrides
+	};
+}
+
+/** User that also has a profile (and optionally a role). */
+export function mockUserWithProfile(overrides?: Record<string, unknown>) {
+	return mockUser({
+		profile: {
+			id: 'profile-1',
+			userId: 'user-1',
+			firstName: 'Jane',
+			lastName: 'Doe',
+			phoneNumber: '555-0100'
+		},
+		...overrides
+	});
+}