feat(todo-cleanup): dated-seal archiving and planning-line strip on convert

Two batched changes to the todo hygiene tooling.

Dated-seal archiving: --archive-done aging now keeps one month in-file (retain default 7 → 31, named as tc-archive-retain-days-default) and a new --seal renames the working task-archive.org to resolved-YYYY-MM-DD.org beside it, letting the next aging start a fresh working file. Dating the sealed file by the seal run rather than the calendar quarter is what avoids mislabeling a task closed late in a quarter and archived after the boundary. The unparseable-CLOSED case is now explicit in the contract: a keyword-complete task with no readable close date ages out too. The sealed file inherits the todo file's gitignore status.

Planning-line strip: --convert-subtasks now drops the whole planning line when it rewrites a done sub-task to a dated event-log entry, not just the CLOSED cookie. A dated-log heading carries its date in the heading, so an active SCHEDULED/DEADLINE left on it pins the finished entry to the agenda as weeks-overdue forever (org renders any active planning timestamp, keyword or not). New lint-org checker dated-log-heading-active-timestamp backstops any that predate this. todo-format.md's sub-task and VERIFY completion rules gain the strip step.

1 files changed, 37 insertions, 0 deletions

diff --git a/.ai/scripts/lint-org.el b/.ai/scripts/lint-org.el
index 55727ef..47e8bf1 100644
--- a/.ai/scripts/lint-org.el
+++ b/.ai/scripts/lint-org.el
@@ -39,6 +39,7 @@
 ;;   malformed-priority-cookie         [#x]-shaped token org rejected
 ;;   level2-done-without-closed        completed level-2 task with no CLOSED
 ;;   subtask-done-not-dated            level-3+ done sub-task still a DONE keyword
+;;   dated-log-heading-active-timestamp  dated-log heading with a live SCHEDULED/DEADLINE
 ;;   (anything else)                   surfaced as judgment with checker name
 ;;
 ;; Output format on stdout:
@@ -551,6 +552,41 @@ Emits one judgment item per offending heading (checker
          "level-3+ done sub-task should be a dated event-log entry (todo-format.md): run todo-cleanup.el --convert-subtasks to rewrite it")))))
 
 ;;; ---------------------------------------------------------------------------
+;;; dated-log heading with a stale active planning timestamp (todo-format.md)
+;;
+;; The mechanical backstop for the planning-line-strip rule.  A dated event-log
+;; heading (`<stars> YYYY-MM-DD Day @ ...', no TODO keyword) records completed
+;; work — its date lives in the heading.  An active `<...>' SCHEDULED or DEADLINE
+;; left on it pins the entry to the agenda forever: org renders any headline with
+;; an active planning timestamp, keyword or not, so a stale SCHEDULED shows as
+;; weeks-overdue long after the work is done.  Invisible to a keyword scan (no
+;; TODO) and it survives --archive-done, so nothing else catches it.  The
+;; completion rewrite and todo-cleanup --convert-subtasks now strip the planning
+;; line; this flags any that slipped through before that landed, the same way
+;; subtask-done-not-dated backstops the depth rule.  Judgment-only.
+
+(defun lo--check-dated-log-active-timestamp ()
+  "Flag a dated event-log heading that still carries an active SCHEDULED/DEADLINE.
+The heading matches `<stars> YYYY-MM-DD Day @ ...' with no TODO keyword; an
+active `<...>' planning timestamp in its entry is the defect. An inactive
+`[...]' timestamp is ignored (org doesn't render it on the agenda). Emits one
+judgment item per offending heading (checker `dated-log-heading-active-timestamp')."
+  (save-excursion
+    (goto-char (point-min))
+    (let ((case-fold-search nil))
+      (while (re-search-forward
+              "^\\*+ [0-9]\\{4\\}-[0-9]\\{2\\}-[0-9]\\{2\\} [A-Za-z]+ @ " nil t)
+        (let ((hline (line-number-at-pos))
+              (entry-end (save-excursion (outline-next-heading) (point))))
+          (save-excursion
+            (forward-line 1)
+            (when (re-search-forward
+                   "^[ \t]*\\(?:SCHEDULED\\|DEADLINE\\):[ \t]*<" entry-end t)
+              (lo--emit-judgment
+               'dated-log-heading-active-timestamp hline
+               "dated-log heading carries an active SCHEDULED/DEADLINE — org renders any active planning timestamp (keyword or not), so it stays on the agenda as weeks-overdue; delete the planning line (todo-format.md)"))))))))
+
+;;; ---------------------------------------------------------------------------
 ;;; File processing
 
 (defun lo--backup (file)
@@ -592,6 +628,7 @@ left unmodified and mechanical entries are recorded with :preview t."
           (lo--check-malformed-priority-cookies)
           (lo--check-level2-done-without-closed)
           (lo--check-subtask-done-not-dated)
+          (lo--check-dated-log-active-timestamp)
           (when (and (not lo-check-only) (buffer-modified-p))
             (save-buffer)))
       (with-current-buffer buf (set-buffer-modified-p nil))