feat(gptel): Add Kimi Code backend for gptel-magit integration

Configure gptel-magit with a dedicated Kimi-Code backend using
api.kimi.com endpoint with Roo Code headers for magit commit message
generation

lisp/init-gptel.el

@@ -126,6 +126,30 @@ from the last 1500 characters of the buffer."
   (add-to-list 'gptel-agent-dirs "~/.emacs.d/lisp/" t)
   (gptel-agent-update))
 
+(use-package gptel-magit
+  :hook
+  (magit-mode . gptel-magit-install)
+  :init
+  (with-eval-after-load 'gptel
+    (gptel-make-openai "Kimi-Code-magit"
+      :host "api.kimi.com"
+      :endpoint "/coding/v1/chat/completions"
+      :protocol "https"
+      :key (lambda ()
+             (auth-source-pick-first-password :host "api.kimi.com" :user "apikey"))
+      :stream t
+      :models '((kimi-for-coding))
+      :request-params '(:thinking (:type "disabled"))
+      :header (lambda (_)
+		(when-let ((key (gptel--get-api-key)))
+                  `(("User-Agent" . "RooCode/3.30.3")
+                    ("HTTP-Referer" . "https://github.com/RooVetGit/Roo-Cline")
+                    ("X-Title" . "Roo Code")
+                    ("Authorization" . ,(concat "Bearer " key))))))
+
+    (setq gptel-magit-model 'kimi-for-coding
+          gptel-magit-backend (gptel-get-backend "Kimi-Code-magit"))))
+
 (provide 'init-gptel)
 
 ;;; init-gptel.el ends here