fix(minimax): use correct API endpoint and format

MiniMax has updated their API. The previous configuration used an
incorrect endpoint (api.minimax.io/anthropic) with anthropic-messages
format, which no longer works.

Changes:
- Update MINIMAX_API_BASE_URL to https://api.minimax.chat/v1
- Change API format from anthropic-messages to openai-completions
- Remove minimax from isAnthropicApi check in transcript-policy

This fixes the issue where MiniMax API calls return no results.

src/agents/models-config.providers.ts

@@ -17,7 +17,7 @@ import { discoverVeniceModels, VENICE_BASE_URL } from "./venice-models.js";
 type ModelsConfig = NonNullable<MoltbotConfig["models"]>;
 export type ProviderConfig = NonNullable<ModelsConfig["providers"]>[string];
 
-const MINIMAX_API_BASE_URL = "https://api.minimax.io/anthropic";
+const MINIMAX_API_BASE_URL = "https://api.minimax.chat/v1";
 const MINIMAX_DEFAULT_MODEL_ID = "MiniMax-M2.1";
 const MINIMAX_DEFAULT_VISION_MODEL_ID = "MiniMax-VL-01";
 const MINIMAX_DEFAULT_CONTEXT_WINDOW = 200000;
@@ -244,7 +244,7 @@ export function normalizeProviders(params: {
 function buildMinimaxProvider(): ProviderConfig {
   return {
     baseUrl: MINIMAX_API_BASE_URL,
-    api: "anthropic-messages",
+    api: "openai-completions",
     models: [
       {
         id: MINIMAX_DEFAULT_MODEL_ID,

src/agents/transcript-policy.ts

@@ -51,7 +51,8 @@ function isOpenAiProvider(provider?: string | null): boolean {
 function isAnthropicApi(modelApi?: string | null, provider?: string | null): boolean {
   if (modelApi === "anthropic-messages") return true;
   const normalized = normalizeProviderId(provider ?? "");
-  return normalized === "anthropic" || normalized === "minimax";
+  // MiniMax now uses openai-completions API, not anthropic-messages
+  return normalized === "anthropic";
 }
 
 function isMistralModel(params: { provider?: string | null; modelId?: string | null }): boolean {