refactor(ai): simplify gptel backend configuration

configs/init-ai.el

@@ -14,11 +14,11 @@
   :defer nil
   :config
   (when (getenv "GEMINI_KEY")
-    (setq gptel-backend (gptel-make-gemini "Gemini"
+    (gptel-make-gemini "Gemini"
       :key (getenv "GEMINI_KEY")
-                          :stream t)))
+      :stream t))
 
-  (setq gptel-backend (gptel-make-openai "llama.cpp"
+  (gptel-make-openai "llama.cpp"
     :stream t
     :protocol "http"
     :host "127.0.0.1:1945"
@@ -38,10 +38,9 @@
               "gemma-4-E2B"
               "gemma-4-E4B-UNCENSORED"
               "gemma-4-E4B"
-                                  "gptoss-20b")))
+              "gptoss-20b"))
 
-  (setq gptel-model 'gemma4:31b-cloud
-        gptel-backend (gptel-make-ollama "Ollama"
+  (gptel-make-ollama "Ollama"
     :host "localhost:11434"
     :stream t
     :request-params '(:think :json-false)
@@ -50,7 +49,7 @@
               "kimi-k2.6:cloud"
               "gpt-oss:20b-cloud"
               "minimax-m2.5:cloud"
-                                  "qwen3-coder-next:cloud")))
+              "qwen3-coder-next:cloud"))
 
   ;; Backend opencode-go: suscripción OpenCode Go vía endpoint OpenAI-compatible
   (defun kj-opencode-go-key ()
@@ -84,6 +83,10 @@
                          north-mini-code-free nemotron-3-ultra-free
                          ling-3.0-flash-free laguna-s-2.1-free))
 
+  ;; Backend y modelo por defecto
+  (setq gptel-backend (gptel-get-backend "OpenCode Go")
+        gptel-model 'deepseek-v4-flash)
+
   (setq gptel-default-mode 'markdown-mode
         gptel-prompt-prefix-alist
         '((markdown-mode . "# User\n\n")