fix(todo-cleanup): read priority via org-heading-components, not regex

The first take walked the heading line with a plain `\[#\([A-Z]\)\]` regex, which matched any cookie-shaped substring anywhere in the line. Dated-log headings can carry that shape inside the title — e.g. "Reprioritized children =[#D]= → =[#B]= to match parent" quotes earlier and new priorities verbatim, and the script read =[#D]= as if it were the heading's own priority cookie.

`(nth 3 (org-heading-components))` only returns a priority when the cookie sits in canonical position (right after the stars or the optional TODO keyword), which is the only place org itself recognizes it. That's the right primitive here.

Surfaced via smoke-testing --check-child-priority against ~/projects/work/todo.org: 10 candidates dropped to 9 once the dated-log heading inside the Whisper parent stopped getting flagged. New ert test tc-sync-ignores-cookie-shaped-text-in-title covers the case directly.

1 files changed, 23 insertions, 1 deletions

diff --git a/.ai/scripts/tests/test-todo-cleanup.el b/.ai/scripts/tests/test-todo-cleanup.el
index 2a9184d..5d43f97 100644
--- a/.ai/scripts/tests/test-todo-cleanup.el
+++ b/.ai/scripts/tests/test-todo-cleanup.el
@@ -417,6 +417,16 @@ in ISSUES, in document order."
 *** TODO [#B] Child equal
 ")
 
+;; A dated-log heading inside a parent task whose title quotes other priorities
+;; in =[#X]= verbatim. Those quoted cookies must NOT be read as the heading's
+;; own priority — the cookie has to sit in canonical position to count.
+(defconst tc-test--sync-cookie-in-title "\
+* Open Work
+** TODO [#B] Parent
+*** 2026-05-14 Reprioritized children =[#D]= → =[#B]= to match parent
+*** TODO [#D] Regular drifted child
+")
+
 ;;; ---------------------------------------------------------------------------
 ;;; Sync-child-priority tests
 
@@ -466,13 +476,25 @@ in ISSUES, in document order."
     (should (= 0 (plist-get out :bumped)))
     (should (equal tc-test--sync-no-change (plist-get out :result)))))
 
+(ert-deftest tc-sync-ignores-cookie-shaped-text-in-title ()
+  (let* ((out (tc-test--sync tc-test--sync-cookie-in-title))
+         (res (plist-get out :result)))
+    ;; Only the real drifted child bumps; the dated-log heading with
+    ;; =[#D]= / =[#B]= verbatim text in its title is untouched.
+    (should (= 1 (plist-get out :bumped)))
+    (should (equal "B" (tc-test--priority-of res "Regular drifted child")))
+    ;; Substring still appears in the dated-log heading; the heading itself
+    ;; was not rewritten.
+    (should (string-match-p "Reprioritized children =\\[#D\\]= → =\\[#B\\]= to match parent" res))))
+
 (ert-deftest tc-sync-is-idempotent ()
   (dolist (fixture (list tc-test--sync-basic
                          tc-test--sync-multi
                          tc-test--sync-no-sync-tag
                          tc-test--sync-priority-less-parent
                          tc-test--sync-cascade
-                         tc-test--sync-no-change))
+                         tc-test--sync-no-change
+                         tc-test--sync-cookie-in-title))
     (let ((once (plist-get (tc-test--sync fixture 1) :result))
           (twice (plist-get (tc-test--sync fixture 2) :result)))
       (should (equal once twice)))))