test: reset to the factory answer instead of casting a new one

A reset mock goes back to the implementation its factory gave it, which
is the fresh session and the open capability these cases want; the cast
replacements grew the test-realism count.

src/app/api/export/__tests__/soft-delete-filter.test.ts

@@ -174,16 +174,10 @@ beforeEach(() => {
   vi.mocked(isModuleEnabled).mockResolvedValue(true);
   vi.mocked(requireModuleEnabled).mockResolvedValue({ enabled: true } as never);
   vi.mocked(getSession).mockResolvedValue(SESSION_OK as never);
-  // A session that signed in just now. Reset, not only cleared: a case below
-  // swaps in a stale session, and `clearAllMocks` keeps the implementation
-  // it left behind for whichever case runs next.
-  vi.mocked(prisma.session.findUnique)
-    .mockReset()
-    .mockImplementation((async () => ({
-      createdAt: new Date(),
-      mfaVerifiedAt: null,
-      reproofAt: null,
-    })) as never);
+  // A session that signed in just now, the factory's own answer. Reset, not
+  // only cleared: a case below swaps in a stale session, and `clearAllMocks`
+  // keeps the implementation it left behind for whichever case runs next.
+  vi.mocked(prisma.session.findUnique).mockReset();
   vi.mocked(checkRateLimit).mockResolvedValue({
     allowed: true,
     limit: 60,

src/app/api/insights/chat/[id]/attachments/__tests__/route.test.ts

@@ -87,15 +87,10 @@ beforeEach(() => {
   vi.clearAllMocks();
   vi.mocked(getSession).mockResolvedValue(SESSION_OK as never);
   vi.mocked(validateAttachmentCandidate).mockResolvedValue({ ok: true });
-  // Open again for every case: the detach case closes every capability, and
-  // `clearAllMocks` would carry that refusal into whichever case runs next.
-  vi.mocked(requireAiCapability)
-    .mockReset()
-    .mockResolvedValue({
-      available: true,
-      reason: null,
-      onDeviceAllowed: true,
-    } as never);
+  // Open again for every case (the factory's own answer): the detach case
+  // closes every capability, and `clearAllMocks` would carry that refusal
+  // into whichever case runs next.
+  vi.mocked(requireAiCapability).mockReset();
 });
 
 describe("POST attach", () => {