feat(08-02): add type-branching guards to SigningPageClient

- Import getFieldType from @/lib/db/schema
- handleFieldClick returns early for non-client-signature fields (defense-in-depth)
- handleSubmit counts only client-signature fields for completeness check
- SigningProgressBar total reflects client-signature count only
- signatureFields added to handleFieldClick and handleSubmit dependency arrays

teressa-copeland-homes/src/app/sign/[token]/_components/SigningPageClient.tsx

@@ -8,6 +8,7 @@ import 'react-pdf/dist/Page/TextLayer.css';
 import { SigningProgressBar } from './SigningProgressBar';
 import { SignatureModal } from './SignatureModal';
 import type { SignatureFieldData } from '@/lib/db/schema';
+import { getFieldType } from '@/lib/db/schema';
 
 // Worker setup — reuse same pattern as PdfViewerWrapper (no CDN, works in local/Docker)
 pdfjs.GlobalWorkerOptions.workerSrc = new URL(
@@ -84,11 +85,16 @@ export function SigningPageClient({
 
   const handleFieldClick = useCallback(
     (fieldId: string) => {
+      const field = signatureFields.find((f) => f.id === fieldId);
+      if (!field) return;
+      // Defense-in-depth: primary protection is the server filter in GET /api/sign/[token]
+      // Only client-signature fields open the modal; Phase 10 will expand this for initials
+      if (getFieldType(field) !== 'client-signature') return;
       if (signedFields.has(fieldId)) return;
       setActiveFieldId(fieldId);
       setModalOpen(true);
     },
-    [signedFields]
+    [signatureFields, signedFields]
   );
 
   const handleModalConfirm = useCallback(
@@ -126,7 +132,10 @@ export function SigningPageClient({
   }, [signatureFields, signedFields]);
 
   const handleSubmit = useCallback(async () => {
-    if (signedFields.size < signatureFields.length || submitting) return;
+    const clientSigFields = signatureFields.filter(
+      (f) => getFieldType(f) === 'client-signature'
+    );
+    if (signedFields.size < clientSigFields.length || submitting) return;
     setSubmitting(true);
     try {
       const res = await fetch(`/api/sign/${token}`, {
@@ -148,7 +157,7 @@ export function SigningPageClient({
       alert('Network error. Please check your connection and try again.');
       setSubmitting(false);
     }
-  }, [signedFields.size, signatureFields.length, submitting, token]);
+  }, [signedFields.size, signatureFields, submitting, token]);
 
   /**
    * Convert PDF user-space coordinates (bottom-left origin) to screen overlay position.
@@ -325,7 +334,7 @@ export function SigningPageClient({
 
       {/* Sticky progress bar */}
       <SigningProgressBar
-        total={signatureFields.length}
+        total={signatureFields.filter((f) => getFieldType(f) === 'client-signature').length}
         signed={signedFields.size}
         onJumpToNext={handleJumpToNext}
         onSubmit={handleSubmit}