fix(ai-config): hook gptel-magit wiring per-feature, not on magit

The wiring keyed on `with-eval-after-load 'magit` fires while two
of its three references are still undefined.  `magit.el` calls
`(provide 'magit)` BEFORE its `cl-eval-when (load eval)` block
requires `magit-commit` and `magit-stash`.  At that moment the
`magit-commit` transient prefix doesn't exist, and
`transient-append-suffix` silently no-ops on missing prefixes
(default `transient-error-on-insert-failure` is nil).  The "g
Generate commit" and "x Explain" suffixes never landed.  Only the
M-g binding worked, because `git-commit` IS required before
provide.

Three per-feature hooks replace the single `'magit` hook: one each
on `git-commit`, `magit-commit`, and `magit-diff`.  Each hooks the
exact dependency the wiring needs, side-stepping the load-order
race entirely.

The companion test was rewritten to check `after-load-alist`
registration rather than drive the hooks through `provide`.  Emacs
30 batch mode doesn't fire registered `eval-after-load` callbacks
on `provide` alone -- only an actual `load` does.  Inspecting the
registration is the stronger guard anyway: the regression is "a
single `'magit` hook," and the right shape of that check is "no
entry under `magit`, entries under `git-commit`, `magit-commit`,
`magit-diff`."

1 files changed, 13 insertions, 6 deletions

diff --git a/modules/ai-config.el b/modules/ai-config.el
index bc896704c..0ffee799c 100644
--- a/modules/ai-config.el
+++ b/modules/ai-config.el
@@ -449,9 +449,14 @@ Works for any buffer, whether it's visiting a file or not."
 
 ;;; -------------------------------- GPTel-Magit --------------------------------
 
-;; `:init' wires the bindings as soon as magit loads, so M-g and the transient
-;; suffixes are ready before any keystroke.  `:commands' + `:defer t' delays
-;; loading gptel-magit itself until one of the entry points is invoked.
+;; Each integration point waits on its actual dependency, not on `magit'
+;; broadly.  `magit.el' calls `(provide 'magit)' BEFORE its
+;; `cl-eval-when (load eval) ...' block requires `magit-commit' and
+;; `magit-stash', so a single `with-eval-after-load 'magit' fires while
+;; the transient prefixes the wiring references are still undefined.
+;; `transient-append-suffix' silently no-ops on missing prefixes (it
+;; calls `message' unless `transient-error-on-insert-failure' is set),
+;; which is how the failure stayed invisible.
 ;;
 ;; Keys:
 ;;   M-g  — generate commit message (in commit message buffer)
@@ -464,10 +469,12 @@ Works for any buffer, whether it's visiting a file or not."
              gptel-magit-commit-generate
              gptel-magit-diff-explain)
   :init
-  (with-eval-after-load 'magit
-    (define-key git-commit-mode-map (kbd "M-g") #'gptel-magit-generate-message)
+  (with-eval-after-load 'git-commit
+    (define-key git-commit-mode-map (kbd "M-g") #'gptel-magit-generate-message))
+  (with-eval-after-load 'magit-commit
     (transient-append-suffix 'magit-commit #'magit-commit-create
-      '("g" "Generate commit" gptel-magit-commit-generate))
+      '("g" "Generate commit" gptel-magit-commit-generate)))
+  (with-eval-after-load 'magit-diff
     (transient-append-suffix 'magit-diff #'magit-stash-show
       '("x" "Explain" gptel-magit-diff-explain))))