fix model mismatch: validate selected model exists on custom API, fallback to default if not

src/config.js

@@ -80,9 +80,29 @@ export async function getAPIConfig() {
 			
 			if (customBaseURL && customAPIKey) {
 				// Import model functions to get the currently selected model
-				const { getSelectedModel } = await import("./models.js");
+				const { getSelectedModel, modelRegistry } = await import("./models.js");
 				const selectedModel = getSelectedModel();
 				
+				// Check if the selected model is from the custom API endpoint
+				const selectedModelEntry = Object.entries(modelRegistry).find(([uniqueId, data]) => 
+					data.modelName === selectedModel && data.endpointId === customBaseURL
+				);
+				
+				if (!selectedModelEntry) {
+					console.warn("⚠️ Selected model not available on custom API, falling back to default");
+					// Return default configuration instead
+					console.log("🏠 Using DEFAULT Hermes API (model mismatch)");
+					return {
+						isCustom: false,
+						endpoints: VLLM_ENDPOINTS,
+						model: MODEL,
+						apiKey: API_KEY,
+						headers: {
+							"Content-Type": "application/json"
+						}
+					};
+				}
+				
 				console.log("🔧 Using CUSTOM API:", {
 					endpoint: customBaseURL,
 					model: selectedModel,