feat: payment PDF extraction, import, and remittance tracking

- Add Upload Payment Documents section with Extract & Download (Excel)
  and Extract & Import (database) buttons
- PDF extractor (pdfplumber) parses MassHealth RA PDFs: two-pass
  strategy joins summary-page ICN/patient map with detail-page
  procedure data (CDT code, paid code, tooth, date, allowed amount)
- RA cover-page summary (Payee ID, RA #, Payment Amount, etc.)
  included as separate Excel sheet; numeric values written as numbers
- Backend PDF import route groups rows by Member #, finds/creates
  patient, creates Payment + ServiceLines with ICN per procedure
- Add icn, paidCode, allowedAmount fields to ServiceLine schema
- Payments table: status simplified to Paid in Full / Balance;
  adjustment auto-computed on mhPaidAmount/copayment change;
  Paid in Full and Revert buttons with confirmation dialogs
- Edit Payment modal: shows ICN, Paid Code, Allowed Amount per line
- PDF Import badge distinguishes from OCR imports in payments table

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

apps/Backend/src/routes/payments.ts

@@ -442,12 +442,19 @@ router.patch(
         return res.status(400).json({ message: "Invalid mhPaidAmount value" });
       }
 
+      const existing = await prisma.payment.findUnique({ where: { id: paymentId } });
+      if (!existing) return res.status(404).json({ message: "Payment not found" });
+
+      const totalBilled  = Number(existing.totalBilled);
+      const copayment    = Number(existing.copayment ?? 0);
+      const adjustment   = Math.max(0, totalBilled - mhPaidAmount - copayment);
+
       const updated = await prisma.payment.update({
         where: { id: paymentId },
-        data: { mhPaidAmount, updatedById: userId },
+        data: { mhPaidAmount, adjustment, updatedById: userId },
       });
 
-      return res.json({ ...updated, mhPaidAmount: Number(updated.mhPaidAmount) });
+      return res.json({ ...updated, mhPaidAmount: Number(updated.mhPaidAmount), adjustment: Number(updated.adjustment) });
     } catch (err: unknown) {
       const message = err instanceof Error ? err.message : "Failed to update MH paid amount";
       return res.status(500).json({ message });
@@ -469,12 +476,19 @@ router.patch(
         return res.status(400).json({ message: "Invalid copayment value" });
       }
 
+      const existing = await prisma.payment.findUnique({ where: { id: paymentId } });
+      if (!existing) return res.status(404).json({ message: "Payment not found" });
+
+      const totalBilled  = Number(existing.totalBilled);
+      const mhPaidAmount = Number(existing.mhPaidAmount ?? 0);
+      const adjustment   = Math.max(0, totalBilled - mhPaidAmount - val);
+
       const updated = await prisma.payment.update({
         where: { id: paymentId },
-        data: { copayment: val, updatedById: userId },
+        data: { copayment: val, adjustment, updatedById: userId },
       });
 
-      return res.json({ ...updated, copayment: Number(updated.copayment) });
+      return res.json({ ...updated, copayment: Number(updated.copayment), adjustment: Number(updated.adjustment) });
     } catch (err: unknown) {
       const message = err instanceof Error ? err.message : "Failed to update copayment";
       return res.status(500).json({ message });