feat: add default models when setting up mux-gateway coupon code

When a user sets their couponCode for mux-gateway for the first time,
automatically add some default models to help them get started:
- anthropic/claude-sonnet-4-20250514
- anthropic/claude-3-5-haiku-20241022
- openai/gpt-4.1
- openai/o4-mini

Author: ibetitsmike

src/node/services/providerService.ts

@@ -111,6 +111,14 @@ export class ProviderService {
       // Load current providers config or create empty
       const providersConfig = this.config.loadProvidersConfig() ?? {};
 
+      // Track if this is first time setting couponCode for mux-gateway
+      const isFirstMuxGatewayCoupon =
+        provider === "mux-gateway" &&
+        keyPath.length === 1 &&
+        keyPath[0] === "couponCode" &&
+        value !== "" &&
+        !providersConfig[provider]?.couponCode;
+
       // Ensure provider exists
       if (!providersConfig[provider]) {
         providersConfig[provider] = {};
@@ -136,6 +144,19 @@ export class ProviderService {
         }
       }
 
+      // Add default models when setting up mux-gateway for the first time
+      if (isFirstMuxGatewayCoupon) {
+        const providerConfig = providersConfig[provider] as Record<string, unknown>;
+        if (!providerConfig.models || (providerConfig.models as string[]).length === 0) {
+          providerConfig.models = [
+            "anthropic/claude-sonnet-4-5-20250514",
+            "anthropic/claude-opus-4-5-20250514",
+            "openai/gpt-5.1",
+            "openai/gpt-5.1-codex",
+          ];
+        }
+      }
+
       // Save updated config
       this.config.saveProvidersConfig(providersConfig);