feat: add Selenium Settings page to configure paymentGroupId per office

Adds a new Settings → Advanced → Selenium Settings page where the office
name (paymentGroupId) used in United/DentalHub portal dropdowns can be
configured without touching code. Previously hardcoded as "Summit Dental
Care"; now injected from DB into the three United workers at job dispatch.

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

packages/db/shared/schemas/results/ServiceLineTransactionFindFirstResult.schema.ts

@@ -0,0 +1,16 @@
+import * as z from 'zod';
+export const ServiceLineTransactionFindFirstResultSchema = z.nullable(z.object({
+  id: z.number().int(),
+  paymentId: z.number().int(),
+  serviceLineId: z.number().int(),
+  transactionId: z.string().optional(),
+  paidAmount: z.number(),
+  adjustedAmount: z.number(),
+  method: z.unknown(),
+  receivedDate: z.date(),
+  payerName: z.string().optional(),
+  notes: z.string().optional(),
+  createdAt: z.date(),
+  payment: z.unknown(),
+  serviceLine: z.unknown()
+}));