feat: show routed model name when using openrouter/free

When the configured model is a routing endpoint like 'openrouter/free',
the actual model used (e.g. 'upstage/solar-pro-3:free') is returned in
the LLM response's 'model' field. We now extract that and display it as:

  Responded by upstage/solar-pro-3:free model from openrouter/free

For any other model (e.g. 'llama3', 'gemma2'), we still show just:

  Responded by llama3

Implementation:
- LLM client returns both requestedModel and actualModel
- API endpoint builds a display-friendly modelLabel
- Frontend uses modelLabel for the attribution line

src/lib/llm.ts

@@ -21,7 +21,8 @@ export interface ConvertResult {
 	converted: string;
 	publicSystemPrompt: string;
 	publicUserMessage: string;
-	model: string;
+	requestedModel: string;
+	actualModel: string | null;
 }
 
 const INPUT_TAG_START = '###### USER INPUT START ######';
@@ -100,10 +101,15 @@ export async function convertText(
 		throw new Error('LLM returned empty response');
 	}
 
+	// OpenRouter's free router returns the actual model used in data.model
+	// e.g. requested "openrouter/free" -> actual "upstage/solar-pro-3:free"
+	const actualModel = (typeof data.model === 'string' && data.model !== merged.model) ? data.model : null;
+
 	return {
 		converted,
 		publicSystemPrompt: buildPublicSystemPrompt(styleModifier, intensityInstruction),
 		publicUserMessage: text,
-		model: merged.model
+		requestedModel: merged.model,
+		actualModel
 	};
 }

src/lib/types.ts

@@ -24,7 +24,7 @@ export interface ConversionResponse {
 	intensity: number;
 	systemPrompt: string;
 	userMessage: string;
-	model: string;
+	modelLabel: string;
 }
 
 export interface LLMConfig {

src/routes/+page.svelte

@@ -49,7 +49,7 @@
 	let error = $state('');
 	let systemPrompt = $state('');
 	let userMessage = $state('');
-	let modelName = $state('');
+	let modelLabel = $state('');
 	let showPrompt = $state(saved?.showPrompt ?? false);
 	let copied = $state(false);
 
@@ -83,7 +83,7 @@
 		outputText = '';
 		systemPrompt = '';
 		userMessage = '';
-		modelName = '';
+		modelLabel = '';
 		showPrompt = false;
 
 		try {
@@ -107,7 +107,7 @@
 			outputText = result.converted;
 			systemPrompt = result.systemPrompt;
 			userMessage = result.userMessage;
-			modelName = result.model;
+			modelLabel = result.modelLabel;
 		} catch (err) {
 			error = err instanceof Error ? err.message : 'Something went wrong';
 		} finally {
@@ -234,8 +234,8 @@
 				</button>
 			</div>
 			<div class="output-text">{outputText}</div>
-			{#if modelName}
-				<p class="model-attribution">Responded by {modelName}</p>
+			{#if modelLabel}
+				<p class="model-attribution">Responded by {modelLabel}</p>
 			{/if}
 		</div>
 

src/routes/api/convert/+server.ts

@@ -54,7 +54,9 @@ export const POST: RequestHandler = async ({ request }) => {
 			intensity,
 			systemPrompt: result.publicSystemPrompt,
 			userMessage: result.publicUserMessage,
-			model: result.model
+			modelLabel: result.actualModel
+				? `${result.actualModel} model from ${result.requestedModel}`
+				: result.requestedModel
 		};
 
 		return json(response);