fix(org-agenda): hoist cj/timeformat out of the defun it was buried in

cj/timeformat was defvar'd inside cj/add-timestamp-to-org-entry, so the symbol
wasn't special until the command had run once. Until then a let around the call
bound it lexically and never reached the function. I moved it to top level with
a docstring. It has no other callers.

The nested defvar also poisons tests. ERT runs alphabetically, so an earlier
test that calls the command makes the symbol special retroactively. A later
special-variable-p check then passes on test ordering rather than on the code,
reading green in a full-file run and red in isolation. The new guard snapshots
special-variable-p into a defconst at load, before any test body runs.

I filled in the missing coverage: point and the following line survive the
insert, empty and unicode time strings, an empty buffer, and a read-only buffer
signalling rather than dropping the stamp. The empty-string case pins a trailing
space (current behavior, characterized rather than changed).

1 files changed, 4 insertions, 1 deletions

diff --git a/modules/org-agenda-config.el b/modules/org-agenda-config.el
index d4407b28..632184e5 100644
--- a/modules/org-agenda-config.el
+++ b/modules/org-agenda-config.el
@@ -383,11 +383,14 @@ The agenda is rebuilt from all sources before display, including:
 ;; ------------------------- Add Timestamp To Org Entry ------------------------
 ;; simply adds a timestamp to put the org entry on an agenda
 
+(defvar cj/timeformat "%Y-%m-%d %a"
+  "Date format for the stamp `cj/add-timestamp-to-org-entry' inserts.
+Must stay an org-readable date so the stamped line reaches the agenda.")
+
 (defun cj/add-timestamp-to-org-entry (s)
   "Add an event with time S to appear underneath the line-at-point.
 This allows a line to show in an agenda without being scheduled or a deadline."
   (interactive "sTime: ")
-  (defvar cj/timeformat "%Y-%m-%d %a")
   (org-end-of-line)
   (save-excursion
     (open-line 1)