feat: update models and prompts

shiny new model imported.
- gpt-5 for daily use
- o3 for complex questions (with high reasoning effort)

Note: gpt-5 model does not support customized temperature, so it's
removed from the api call parameters

botcmd_reason.go

@@ -29,7 +29,7 @@ func handleReasonCmd(c tele.Context) error {
 	}
 
 	req := openai.ChatRequest{
-		Model: openai.ModelO4Mini,
+		Model: openai.ModelO3,
 		Messages: []openai.ChatMessage{
 			{
 				Role:    openai.ChatRoleUser,