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/objects/PaymentCreateWithoutServiceLineTransactionsInput.schema.ts

@@ -46,6 +46,33 @@ const makeSchema = () => z.object({
 ]).refine((v) => isValidDecimalInput(v), {
   message: "Field 'totalDue' must be a Decimal",
 }),
+  mhPaidAmount: z.union([
+  z.number(),
+  z.string(),
+  z.instanceof(Decimal),
+  z.instanceof(Prisma.Decimal),
+  DecimalJSLikeSchema,
+]).refine((v) => isValidDecimalInput(v), {
+  message: "Field 'mhPaidAmount' must be a Decimal",
+}).optional().nullable(),
+  copayment: z.union([
+  z.number(),
+  z.string(),
+  z.instanceof(Decimal),
+  z.instanceof(Prisma.Decimal),
+  DecimalJSLikeSchema,
+]).refine((v) => isValidDecimalInput(v), {
+  message: "Field 'copayment' must be a Decimal",
+}).optional(),
+  adjustment: z.union([
+  z.number(),
+  z.string(),
+  z.instanceof(Decimal),
+  z.instanceof(Prisma.Decimal),
+  DecimalJSLikeSchema,
+]).refine((v) => isValidDecimalInput(v), {
+  message: "Field 'adjustment' must be a Decimal",
+}).optional(),
   status: PaymentStatusSchema.optional(),
   notes: z.string().optional().nullable(),
   icn: z.string().optional().nullable(),