fix: new edge cases with function calls / tools

src/backend/src/modules/puterai/AIChatService.js

@@ -551,6 +551,10 @@ class AIChatService extends BaseService {
     async moderate ({ messages }) {
         for ( const msg of messages ) {
             const texts = [];
+            
+            // Function calls have no content
+            if ( msg.content === null ) continue;
+
             if ( typeof msg.content === 'string' ) texts.push(msg.content);
             else if ( typeof msg.content === 'object' ) {
                 if ( Array.isArray(msg.content) ) {

src/backend/src/modules/puterai/OpenAICompletionService.js

@@ -258,6 +258,9 @@ class OpenAICompletionService extends BaseService {
                 throw new Error('each message must be a string or an object');
             }
             if ( ! msg.role ) msg.role = 'user';
+            if ( msg.role === 'assistant' && ! msg.content ) {
+                continue;
+            }
             if ( ! msg.content ) {
                 throw new Error('each message must have a `content` property');
             }