fix(portal): validate waitlist preferredTime/preferredDate, return 400 on bad input (GRO-2211)

createWaitlistEntrySchema/updateWaitlistEntrySchema declared preferredTime/
preferredDate as bare z.string(), so a malformed value (e.g. a full ISO
datetime) was inserted straight into the Postgres time/date columns, throwing
a DateTimeParseError that surfaced as an unhandled 500.

Constrain both fields with regexes (HH:MM[:SS] / YYYY-MM-DD) so zValidator
rejects bad input with 400 before it hits the DB, and normalize HH:MM to
HH:MM:SS on insert/update. Adds waitlist tests covering the 400 paths and
HH:MM normalization.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/__tests__/waitlist.test.ts

@@ -184,6 +184,66 @@ describe("POST /portal/waitlist", () => {
     expect(insertedValues).toHaveLength(1);
   });
 
+  it("normalizes HH:MM:SS preferredTime and returns 201 (GRO-2211)", async () => {
+    selectSessionRow = ACTIVE_SESSION;
+    const res = await jsonRequest("POST", "/portal/waitlist", {
+      petId: VALID_UUID_3,
+      serviceId: VALID_UUID_4,
+      preferredDate: "2026-03-25",
+      preferredTime: "10:00:00",
+    }, { "X-Impersonation-Session-Id": VALID_UUID_5 });
+    expect(res.status).toBe(201);
+    expect(insertedValues[0]?.preferredTime).toBe("10:00:00");
+  });
+
+  it("normalizes HH:MM preferredTime to HH:MM:SS before insert (GRO-2211)", async () => {
+    selectSessionRow = ACTIVE_SESSION;
+    const res = await jsonRequest("POST", "/portal/waitlist", {
+      petId: VALID_UUID_3,
+      serviceId: VALID_UUID_4,
+      preferredDate: "2026-03-25",
+      preferredTime: "10:00",
+    }, { "X-Impersonation-Session-Id": VALID_UUID_5 });
+    expect(res.status).toBe(201);
+    expect(insertedValues[0]?.preferredTime).toBe("10:00:00");
+  });
+
+  it("returns 400 (not 500) for a full ISO datetime preferredTime (GRO-2211)", async () => {
+    selectSessionRow = ACTIVE_SESSION;
+    const res = await jsonRequest("POST", "/portal/waitlist", {
+      petId: VALID_UUID_3,
+      serviceId: VALID_UUID_4,
+      preferredDate: "2026-03-25",
+      preferredTime: "2026-06-09T10:00:00.000Z",
+    }, { "X-Impersonation-Session-Id": VALID_UUID_5 });
+    expect(res.status).toBe(400);
+    expect(insertedValues).toHaveLength(0);
+  });
+
+  it("returns 400 for a malformed preferredDate (GRO-2211)", async () => {
+    selectSessionRow = ACTIVE_SESSION;
+    const res = await jsonRequest("POST", "/portal/waitlist", {
+      petId: VALID_UUID_3,
+      serviceId: VALID_UUID_4,
+      preferredDate: "03/25/2026",
+      preferredTime: "10:00",
+    }, { "X-Impersonation-Session-Id": VALID_UUID_5 });
+    expect(res.status).toBe(400);
+    expect(insertedValues).toHaveLength(0);
+  });
+
+  it("returns 400 for an out-of-range preferredTime (GRO-2211)", async () => {
+    selectSessionRow = ACTIVE_SESSION;
+    const res = await jsonRequest("POST", "/portal/waitlist", {
+      petId: VALID_UUID_3,
+      serviceId: VALID_UUID_4,
+      preferredDate: "2026-03-25",
+      preferredTime: "25:99",
+    }, { "X-Impersonation-Session-Id": VALID_UUID_5 });
+    expect(res.status).toBe(400);
+    expect(insertedValues).toHaveLength(0);
+  });
+
   it("returns 401 without session", async () => {
     const res = await jsonRequest("POST", "/portal/waitlist", {
       petId: VALID_UUID_3,
@@ -258,6 +318,16 @@ describe("PATCH /portal/waitlist/:id", () => {
     expect(updatedValues[0]?.status).toBe("cancelled");
   });
 
+  it("returns 400 (not 500) for a full ISO datetime preferredTime on update (GRO-2211)", async () => {
+    selectSessionRow = ACTIVE_SESSION;
+    selectRows = [WAITLIST_ENTRY];
+    const res = await jsonRequest("PATCH", `/portal/waitlist/${VALID_UUID_1}`, {
+      preferredTime: "2026-06-09T10:00:00.000Z",
+    }, { "X-Impersonation-Session-Id": VALID_UUID_5 });
+    expect(res.status).toBe(400);
+    expect(updatedValues).toHaveLength(0);
+  });
+
   it("returns 401 without session", async () => {
     const res = await jsonRequest("PATCH", `/portal/waitlist/${VALID_UUID_1}`, {
       status: "cancelled",