Upgrade from GPT-3.5-turbo to GPT-4o-mini for better performance and cost efficiency

- Updated all 13 OpenAI API calls to use gpt-4o-mini model
- Updated source labels to reflect new model usage
- Benefits: Better performance, more recent training data, improved instruction following
- Cost: Significantly lower (/usr/bin/bash.15//usr/bin/bash.60 vs /usr/bin/bash.50/.50 per 1M tokens)
- Enhanced multilingual support for German/English conversations
- Improved Socratic teaching capabilities for children

html/kidsai/server.js

@@ -125,7 +125,7 @@ app.post('/api/reveal-answer', async (req, res) => {
 
 // Function to get OpenAI-powered educational guidance (Primary)
 async function getOpenAIGuidance(question, language) {
-    console.log('🤖 Calling OpenAI with GPT-3.5-turbo...');
+    console.log('🤖 Calling OpenAI with GPT-4o-mini...');
     
     const isGerman = language === 'de';
     
@@ -139,7 +139,7 @@ async function getOpenAIGuidance(question, language) {
 
     try {
         const completion = await openai.chat.completions.create({
-            model: "gpt-3.5-turbo",
+            model: "gpt-4o-mini",
             messages: [
                 { role: "system", content: systemPrompt },
                 { role: "user", content: userPrompt }
@@ -158,7 +158,7 @@ async function getOpenAIGuidance(question, language) {
             type: 'ai-powered',
             steps: steps,
             encouragement: getRandomEncouragement(language, question),
-            source: 'OpenAI GPT-3.5'
+            source: 'OpenAI GPT-4o-mini'
         };
 
     } catch (error) {
@@ -472,7 +472,7 @@ async function getActualAnswer(question, language) {
     try {
         if (process.env.OPENAI_API_KEY) {
             const completion = await openai.chat.completions.create({
-                model: "gpt-3.5-turbo",
+                model: "gpt-4o-mini",
                 messages: [
                     { role: "system", content: systemPrompt },
                     { role: "user", content: userPrompt }
@@ -487,7 +487,7 @@ async function getActualAnswer(question, language) {
             return {
                 type: 'ai-powered',
                 text: answer.trim(),
-                source: 'OpenAI GPT-3.5'
+                source: 'OpenAI GPT-4o-mini'
             };
         }
     } catch (error) {
@@ -570,7 +570,7 @@ The child is expressing confusion and needs help understanding. Provide a clear,
             if (process.env.OPENAI_API_KEY) {
                 try {
                     const completion = await openai.chat.completions.create({
-                        model: "gpt-3.5-turbo",
+                        model: "gpt-4o-mini",
                         messages: [
                             {
                                 role: "system",
@@ -588,7 +588,7 @@ The child is expressing confusion and needs help understanding. Provide a clear,
                         return res.json({
                             success: true,
                             response: aiResponse,
-                            source: 'OpenAI GPT-3.5 (Confusion Explanation)'
+                            source: 'OpenAI GPT-4o-mini (Confusion Explanation)'
                         });
                     }
                 } catch (openaiError) {
@@ -646,7 +646,7 @@ The child is asking for a definition, explanation, or clarification about locati
             if (process.env.OPENAI_API_KEY) {
                 try {
                     const completion = await openai.chat.completions.create({
-                        model: "gpt-3.5-turbo",
+                        model: "gpt-4o-mini",
                         messages: [
                             {
                                 role: "system",
@@ -664,7 +664,7 @@ The child is asking for a definition, explanation, or clarification about locati
                         return res.json({
                             success: true,
                             response: aiResponse,
-                            source: 'OpenAI GPT-3.5 (Definition Response)'
+                            source: 'OpenAI GPT-4o-mini (Definition Response)'
                         });
                     }
                 } catch (openaiError) {
@@ -726,7 +726,7 @@ IMPORTANT:
         if (process.env.OPENAI_API_KEY) {
             try {
                 const completion = await openai.chat.completions.create({
-                    model: "gpt-3.5-turbo",
+                    model: "gpt-4o-mini",
                     messages: [
                         {
                             role: "system",
@@ -744,7 +744,7 @@ IMPORTANT:
                     return res.json({
                         success: true,
                         response: aiResponse,
-                        source: 'OpenAI GPT-3.5'
+                        source: 'OpenAI GPT-4o-mini'
                     });
                 }
             } catch (openaiError) {
@@ -828,7 +828,7 @@ CHILD'S ANSWER: "${userAnswer}"
 Ask one thoughtful follow-up question that invites the child to explore the topic deeper. The question should spark curiosity and encourage hands-on observation. Give NO answers - just one fascinating question.`;
 
                 const completion = await openai.chat.completions.create({
-                    model: "gpt-3.5-turbo",
+                    model: "gpt-4o-mini",
                     messages: [
                         { role: "system", content: systemPrompt },
                         { role: "user", content: userPrompt }
@@ -844,7 +844,7 @@ Ask one thoughtful follow-up question that invites the child to explore the topi
                     return res.json({
                         success: true,
                         response: aiResponse,
-                        source: 'OpenAI GPT-3.5 Deeper Exploration'
+                        source: 'OpenAI GPT-4o-mini Deeper Exploration'
                     });
                 }
             } catch (openaiError) {