uat→main (PROD): GRO-2157 nav export + GRO-2225/2235 (frozen @4868f18) (#192)

feat: nav export + conflict guard + UAT seed (GRO-2157, GRO-2225, GRO-2235)

Squash-merges PR #192: uat→main PROD promotion.
Freezes at validated SHA 4868f18 (UAT regression GRO-2261 11/11 PASS).
Bundles: GRO-2157 (nav export), GRO-2225 (UAT seed), GRO-2235 (conflict guard).
CTO-reviewed and approved (review #4542).

Co-authored-by: Flea Flicker <22+gb_flea@noreply.git.farh.net>
Co-committed-by: Flea Flicker <22+gb_flea@noreply.git.farh.net>

src/routes/portal.ts

@@ -596,16 +596,32 @@ portalRouter.post(
     const body = c.req.valid("json");
     const clientId = c.get("portalClientId");
 
-    const [entry] = await db
-      .insert(waitlistEntries)
-      .values({
-        clientId,
-        petId: body.petId,
-        serviceId: body.serviceId,
-        preferredDate: body.preferredDate,
-        preferredTime: normalizeTime(body.preferredTime),
-      })
-      .returning();
+    let entry;
+    try {
+      [entry] = await db
+        .insert(waitlistEntries)
+        .values({
+          clientId,
+          petId: body.petId,
+          serviceId: body.serviceId,
+          preferredDate: body.preferredDate,
+          preferredTime: normalizeTime(body.preferredTime),
+        })
+        .returning();
+    } catch (err) {
+      // An exact duplicate active waitlist entry violates the partial unique
+      // index idx_waitlist_active_unique (client_id, pet_id, service_id,
+      // preferred_date, preferred_time WHERE status='active'). postgres-js
+      // surfaces this as SQLSTATE 23505 — return a friendly 409 rather than a
+      // generic 500 (GRO-2235). Unrelated errors still surface as 500.
+      if ((err as { code?: string })?.code === "23505") {
+        return c.json(
+          { error: "You already have a booking for this pet at that date and time." },
+          409
+        );
+      }
+      throw err;
+    }
 
     return c.json(entry, 201);
   }