feat: add Copayment and Adjustment columns to payments table

- Added copayment and adjustment fields (Decimal, default 0) to Payment
  model in schema and directly to DB via ALTER TABLE
- Added PATCH /api/payments/:id/copayment and /adjustment routes
- Added inline-editable Copayment and Adjustment columns after MH Paid
  with same click-to-edit format; Copayment in blue, Adjustment in orange

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

packages/db/shared/schemas/variants/input/Payment.input.ts

@@ -11,6 +11,9 @@ export const PaymentInputSchema = z.object({
     totalPaid: z.number(),
     totalAdjusted: z.number(),
     totalDue: z.number(),
+    mhPaidAmount: z.number().optional().nullable(),
+    copayment: z.number(),
+    adjustment: z.number(),
     status: PaymentStatusSchema,
     notes: z.string().optional().nullable(),
     icn: z.string().optional().nullable(),