fix(ai-config): gptel-model must be a symbol, not a string

The default-backend swap to gpt-5.5 (commit 0f029ab5) set
`gptel-model' as the string "gpt-5.5".  gptel's modeline-display
code calls `symbolp' on the model value and signals
`wrong-type-argument symbolp "gpt-5.5"' on every render, which
manifested as Emacs freezing in the AI-Assistant buffer ("Querying
ChatGPT..." → error in process sentinel → repeated redisplay errors).

Both default-setting sites now use `'gpt-5.5' (interned symbol).
The Anthropic backend tolerated string model names so the original
"claude-opus-4-7" string worked, which is why this hadn't surfaced
before.

1 files changed, 5 insertions, 3 deletions

diff --git a/modules/ai-config.el b/modules/ai-config.el
index cef929c1..050efbd4 100644
--- a/modules/ai-config.el
+++ b/modules/ai-config.el
@@ -150,7 +150,7 @@ Call this only after loading `gptel' so the backend constructors exist."
   ;; Set default backend and model
   (unless gptel-backend
     (setq gptel-backend (or gptel-chatgpt-backend gptel-claude-backend))
-    (setq gptel-model "gpt-5.5")))
+    (setq gptel-model 'gpt-5.5)))
 
 ;; ------------------ GPTel Conversation And Utility Commands ------------------
 
@@ -377,9 +377,11 @@ Works for any buffer, whether it's visiting a file or not."
   (gptel--debug nil)
   :config
   (cj/ensure-gptel-backends)
-  ;; Set ChatGPT (gpt-5.5) as default after initialization
+  ;; Set ChatGPT (gpt-5.5) as default after initialization.  Model
+  ;; must be a symbol -- gptel's modeline-display code calls `symbolp'
+  ;; on it and signals `wrong-type-argument' otherwise.
   (setq gptel-backend gptel-chatgpt-backend)
-  (setq gptel-model "gpt-5.5")
+  (setq gptel-model 'gpt-5.5)
 
   (setq gptel-confirm-tool-calls nil) ;; allow tool access by default