fix: handle internal user preview mode before validating clientId/companyId

When internalUserId is provided in the token payload, the user is viewing
company or client details pages that don't support preview. This should
show the "CRM preview is not available" message instead of throwing an
error about missing clientId or companyId.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

Author: makeitraina

src/app/client-preview/page.tsx

@@ -60,13 +60,17 @@ export default async function ClientPreviewPage({
   const token = tokenParsed.data
   const copilotClient = new CopilotAPI(token)
   const tokenPayload = await copilotClient.getTokenPayload()
-  if (!tokenPayload || !tokenPayload.clientId || !tokenPayload.companyId) {
+  if (!tokenPayload) {
     console.info('Failing token payload', tokenPayload)
     throw new Error('Failed to parse token payload')
   }
   if (getPreviewMode(tokenPayload)) {
     return <NoPreviewSupport />
   }
+  if (!tokenPayload.clientId || !tokenPayload.companyId) {
+    console.info('Missing clientId or companyId in token payload', tokenPayload)
+    throw new Error('Failed to parse token payload')
+  }
 
   const clientId = z.string().uuid().parse(tokenPayload.clientId)