fix: allow claims without appointment + support post/core multi-tooth input

- Make appointmentId nullable/optional in Prisma Zod schema via @zod rich
  comment so claims can be submitted without an existing appointment
- Convert undefined appointmentId to null in all claim form handlers and
  the backend claim creation endpoint
- Add AI classifier rule for expanding one procedure across multiple
  comma-separated tooth numbers (e.g. "post/core on #23, 24, 25, 26")
- Add "post/core" (slash) alias to CDT lookup maps

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

apps/Frontend/src/components/claims/claim-form.tsx

@@ -953,7 +953,7 @@ export function ClaimForm({
       return;
     }
 
-    const appointmentIdToUse = appointmentId;
+    const appointmentIdToUse = appointmentId ?? null;
 
     // 3. Create Claim(if not)
     // Filter out empty service lines (empty procedureCode)
@@ -1092,7 +1092,7 @@ export function ClaimForm({
       return;
     }
 
-    const appointmentIdToUse = appointmentId;
+    const appointmentIdToUse = appointmentId ?? null;
 
     const { uploadedFiles, insuranceSiteKey, npiProvider, ...formToCreateClaim } = f;
     const claimFilesMeta: ClaimFileMeta[] = (uploadedFiles || []).map((file) => ({
@@ -1159,7 +1159,7 @@ export function ClaimForm({
       return;
     }
 
-    const appointmentIdToUse = appointmentId;
+    const appointmentIdToUse = appointmentId ?? null;
 
     const { uploadedFiles, insuranceSiteKey, npiProvider, ...formToCreateClaim } = f;
 
@@ -1226,7 +1226,7 @@ export function ClaimForm({
       return;
     }
 
-    const appointmentIdToUse = appointmentId;
+    const appointmentIdToUse = appointmentId ?? null;
 
     const { uploadedFiles, insuranceSiteKey, npiProvider, ...formToCreateClaim } = f;
 
@@ -1292,7 +1292,7 @@ export function ClaimForm({
       return;
     }
 
-    const appointmentIdToUse = appointmentId;
+    const appointmentIdToUse = appointmentId ?? null;
 
     const { uploadedFiles, insuranceSiteKey, npiProvider, ...formToCreateClaim } = f;
 
@@ -1561,7 +1561,7 @@ export function ClaimForm({
       return;
     }
 
-    const appointmentIdToUse = appointmentId;
+    const appointmentIdToUse = appointmentId ?? null;
 
     const { uploadedFiles, insuranceSiteKey, npiProvider, ...formToSave } = form;
 
@@ -1698,7 +1698,7 @@ export function ClaimForm({
       return;
     }
 
-    const appointmentIdToUse = appointmentId;
+    const appointmentIdToUse = appointmentId ?? null;
 
     const { uploadedFiles, insuranceSiteKey, npiProvider, ...formToCreateClaim } = form;