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, 42 insertions, 0 deletions

diff --git a/.ai/scripts/tests/test-lint-org.el b/.ai/scripts/tests/test-lint-org.el
index 8e3e190..30a79bd 100644
--- a/.ai/scripts/tests/test-lint-org.el
+++ b/.ai/scripts/tests/test-lint-org.el
@@ -739,6 +739,48 @@ missing-rules violation."
          (judgments (lo-test--judgments (plist-get out :issues))))
     (should-not (member 'subtask-done-not-dated (lo-test--checkers judgments)))))
 
+;;; dated-log-heading-active-timestamp check (stale SCHEDULED/DEADLINE on a
+;;; completed dated-log entry — the home 2026-07-17 agenda-pollution bug)
+
+(ert-deftest lo-dated-log-active-scheduled-is-flagged ()
+  "A dated-log entry still carrying an active SCHEDULED is flagged: org renders
+it on the agenda forever despite the missing keyword."
+  (let* ((out (lo-test--run
+               "* Open Work\n\n** TODO [#B] Parent\n*** 2026-06-20 Sat @ 10:00:00 -0500 trip booked\nSCHEDULED: <2026-06-18 Thu>\nBody.\n"))
+         (judgments (lo-test--judgments (plist-get out :issues))))
+    (should (= 0 (plist-get out :fixes)))       ; judgment-only, never auto-fixed
+    (should (member 'dated-log-heading-active-timestamp (lo-test--checkers judgments)))))
+
+(ert-deftest lo-dated-log-active-deadline-is-flagged ()
+  "An active DEADLINE on a dated-log entry is flagged too."
+  (let* ((out (lo-test--run
+               "* Open Work\n\n** TODO [#B] Parent\n*** 2026-06-20 Sat @ 10:00:00 -0500 shipped\nDEADLINE: <2026-06-25 Thu>\n"))
+         (judgments (lo-test--judgments (plist-get out :issues))))
+    (should (member 'dated-log-heading-active-timestamp (lo-test--checkers judgments)))))
+
+(ert-deftest lo-dated-log-clean-entry-not-flagged ()
+  "A dated-log entry with no active planning timestamp is correct — not flagged."
+  (let* ((out (lo-test--run
+               "* Open Work\n\n** TODO [#B] Parent\n*** 2026-06-20 Sat @ 10:00:00 -0500 done cleanly\nBody only.\n"))
+         (judgments (lo-test--judgments (plist-get out :issues))))
+    (should-not (member 'dated-log-heading-active-timestamp (lo-test--checkers judgments)))))
+
+(ert-deftest lo-dated-log-inactive-timestamp-not-flagged ()
+  "An inactive [..] timestamp doesn't render on the agenda, so it isn't flagged —
+only active <..> planning timestamps are the defect."
+  (let* ((out (lo-test--run
+               "* Open Work\n\n** TODO [#B] Parent\n*** 2026-06-20 Sat @ 10:00:00 -0500 recorded\nSCHEDULED: [2026-06-18 Thu]\n"))
+         (judgments (lo-test--judgments (plist-get out :issues))))
+    (should-not (member 'dated-log-heading-active-timestamp (lo-test--checkers judgments)))))
+
+(ert-deftest lo-dated-log-active-scheduled-on-live-todo-not-flagged ()
+  "A live TODO (keyword present) that legitimately carries an active SCHEDULED is
+not a dated-log heading, so this checker leaves it alone."
+  (let* ((out (lo-test--run
+               "* Open Work\n\n** TODO [#B] Parent\n*** TODO [#C] real upcoming task\nSCHEDULED: <2026-06-18 Thu>\n"))
+         (judgments (lo-test--judgments (plist-get out :issues))))
+    (should-not (member 'dated-log-heading-active-timestamp (lo-test--checkers judgments)))))
+
 ;;; ---------------------------------------------------------------------------
 ;;; structural heading checks (org-lint gaps)