feat: add fallback

src/core/config.ts

@@ -13,6 +13,7 @@ interface BotConfig {
     openRouterApiKey: string;
     model: string;
     classificationModel: string;
+    classificationFallbackModels: string[];
     maxTokens: number;
     temperature: number;
   };
@@ -75,6 +76,18 @@ function getBooleanEnvOrDefault(key: string, defaultValue: boolean): boolean {
   return normalized === "1" || normalized === "true" || normalized === "yes";
 }
 
+function getCsvEnvOrDefault(key: string, defaultValues: string[]): string[] {
+  const raw = Bun.env[key];
+  if (!raw) {
+    return defaultValues;
+  }
+
+  return raw
+    .split(",")
+    .map((value) => value.trim())
+    .filter((value) => value.length > 0);
+}
+
 export const config: BotConfig = {
   discord: {
     token: getEnvOrThrow("DISCORD_TOKEN"),
@@ -91,6 +104,10 @@ export const config: BotConfig = {
       "AI_CLASSIFICATION_MODEL",
       "google/gemma-3-12b-it:free"
     ),
+    classificationFallbackModels: getCsvEnvOrDefault("AI_CLASSIFICATION_FALLBACK_MODELS", [
+      "qwen/qwen-2.5-7b-instruct:free",
+      "mistralai/mistral-7b-instruct:free",
+    ]),
     maxTokens: parseInt(getEnvOrDefault("AI_MAX_TOKENS", "500")),
     temperature: parseFloat(getEnvOrDefault("AI_TEMPERATURE", "1.2")),
   },