refactor(org-agenda): extract main-agenda prefix format into a defvar

`org-agenda-custom-commands` inlined `  %i %-15:c%?-15t% s` four times across the "d" command's overdue / high-priority / schedule / priority-B blocks. New `cj/--main-agenda-prefix-format` defvar holds the literal once; every block now references the symbol so a format tweak lands in one place.

Regression test walks the "d" command's blocks and asserts each `org-agenda-prefix-format` cell resolves to the shared symbol -- a block that silently diverges fails the check.

2 files changed, 27 insertions, 4 deletions

diff --git a/modules/org-agenda-config.el b/modules/org-agenda-config.el
index 2c30db0fe..9ff2fd722 100644
--- a/modules/org-agenda-config.el
+++ b/modules/org-agenda-config.el
@@ -279,6 +279,12 @@ If the current buffer isn't an org buffer, inform the user."
 (defvar cj/main-agenda-tasks-title "PRIORITY B"
   "String to announce the schedule section of the main agenda.")
 
+(defvar cj/--main-agenda-prefix-format "  %i %-15:c%?-15t% s"
+  "Prefix format string shared by all blocks of the main daily agenda.
+Inlined across the overdue / high-priority / schedule / priority-B
+blocks of `org-agenda-custom-commands' before the extraction.  Keep
+the four blocks pointing here so a format tweak lands in one place.")
+
 (defun cj/org-skip-subtree-if-habit ()
   "Skip an agenda entry if it has a STYLE property equal to \"habit\"."
   (let ((subtree-end (save-excursion (org-end-of-subtree t))))
@@ -331,11 +337,11 @@ KEYWORDS must be a list of strings."
 		 ((alltodo ""
 				   ((org-agenda-skip-function #'cj/org-agenda-skip-subtree-if-not-overdue)
 					(org-agenda-overriding-header cj/main-agenda-overdue-title)
-					(org-agenda-prefix-format "  %i %-15:c%?-15t% s")))
+					(org-agenda-prefix-format cj/--main-agenda-prefix-format)))
 		  (tags "PRIORITY=\"A\""
 				((org-agenda-skip-function '(org-agenda-skip-entry-if 'todo 'done))
 				 (org-agenda-overriding-header cj/main-agenda-hipri-title)
-				 (org-agenda-prefix-format "  %i %-15:c%?-15t% s")))
+				 (org-agenda-prefix-format cj/--main-agenda-prefix-format)))
 		  (agenda ""
 				  ((org-agenda-start-day "0d")
 				   (org-agenda-span 8)
@@ -345,7 +351,7 @@ KEYWORDS must be a list of strings."
 				   (org-agenda-skip-function
 					'(org-agenda-skip-entry-if 'todo '("CANCELLED")))
 				   (org-agenda-overriding-header cj/main-agenda-schedule-title)
-				   (org-agenda-prefix-format "  %i %-15:c%?-15t% s")))
+				   (org-agenda-prefix-format cj/--main-agenda-prefix-format)))
 		  (alltodo ""
 				   ((org-agenda-skip-function '(or (cj/org-skip-subtree-if-habit)
 												   (cj/org-skip-subtree-if-priority ?A)
@@ -354,7 +360,7 @@ KEYWORDS must be a list of strings."
 												   (cj/org-skip-subtree-if-keyword '("PROJECT"))
 												   (org-agenda-skip-if nil '(scheduled deadline))))
 					(org-agenda-overriding-header cj/main-agenda-tasks-title)
-					(org-agenda-prefix-format "  %i %-15:c%?-15t% s"))))
+					(org-agenda-prefix-format cj/--main-agenda-prefix-format))))
 		 ((org-agenda-compact-blocks nil)))))
 
 
diff --git a/tests/test-org-agenda-config-skip-functions.el b/tests/test-org-agenda-config-skip-functions.el
index 17ee848f3..3c044adbd 100644
--- a/tests/test-org-agenda-config-skip-functions.el
+++ b/tests/test-org-agenda-config-skip-functions.el
@@ -247,5 +247,22 @@ priority-B blocks must not pick up the same skip-function form."
              (skip (cadr (assoc 'org-agenda-skip-function opts))))
         (should-not (equal skip cancelled-form))))))
 
+;;; ---------- prefix-format extracted into a defvar ----------
+
+;;; Normal Cases
+
+(ert-deftest test-org-agenda-config-prefix-format-extracted-to-defvar ()
+  "Normal: every block of the \"d\" command references the shared prefix
+format symbol rather than inlining the literal string.  Catches a
+regression where one block diverges from the others on the format."
+  (let* ((entry (assoc "d" org-agenda-custom-commands))
+         (blocks (nth 2 entry)))
+    (should (boundp 'cj/--main-agenda-prefix-format))
+    (should (stringp cj/--main-agenda-prefix-format))
+    (dolist (b blocks)
+      (let* ((opts (nth 2 b))
+             (fmt-form (cadr (assoc 'org-agenda-prefix-format opts))))
+        (should (eq fmt-form 'cj/--main-agenda-prefix-format))))))
+
 (provide 'test-org-agenda-config-skip-functions)
 ;;; test-org-agenda-config-skip-functions.el ends here