fix: switch GMW AI source from omniroute to 9router

- Change AI_LLM_BASE_URL default from omniroute.imrnes.team to 9router.asepharyana.my.id
- Update AI_LLM_MODEL default from 'text' to 'claude-opus-5' (bare model name
  compatible with 9router/OpenAI-compatible router)
- Update .env.example and inline comments to reflect 9router
- discord-gateway config now matches backend (which already uses 9router)

services/discord-gateway/src/shared/config/index.ts

@@ -149,8 +149,8 @@ export const configSchema = z
     AI_LLM_BASE_URL: z
       .string()
       .url()
-      .default("https://omniroute.imrnes.team/v1"),
-    AI_LLM_MODEL: z.string().default("text"),
+      .default("https://9router.asepharyana.my.id/v1"),
+    AI_LLM_MODEL: z.string().default("claude-opus-5"),
     // Vision uses the SAME router/base URL as text moderation
     // (AI_LLM_BASE_URL) but a different model alias. The dedicated NVIDIA
     // multimodal endpoint was removed.