feat(todo-cleanup): add --convert-subtasks dated-rewrite mode

Rewrites every level-3+ DONE/CANCELLED/FAILED heading into a dated event-log entry from its CLOSED cookie, enforcing the todo-format depth rule that interactive closes and --archive-done (level-2 only) leave unapplied. A new lint-org checker (subtask-done-not-dated) flags stragglers, and the clean-todo, wrap-up, open-tasks, and task-review workflows now run the converter before archiving.

Removing the CLOSED cookie keeps a DEADLINE or SCHEDULED cookie that shares its planning line, rather than dropping the whole line.

From the .emacs.d handoff (2026-07-01 convert-subtasks bundle).

1 files changed, 15 insertions, 4 deletions

diff --git a/.ai/workflows/clean-todo.org b/.ai/workflows/clean-todo.org
index dd33056..a1b2af5 100644
--- a/.ai/workflows/clean-todo.org
+++ b/.ai/workflows/clean-todo.org
@@ -27,7 +27,17 @@ Deletes bogus =- State "X" from "X" [date]= log lines (state didn't actually cha
 
 To preview without writing, run =--check= first: =emacs --batch -q -l .ai/scripts/todo-cleanup.el --check todo.org=.
 
-** Step 2: Archive completed work
+** Step 2: Convert done sub-tasks to dated entries
+
+#+begin_src bash
+emacs --batch -q -l .ai/scripts/todo-cleanup.el --convert-subtasks todo.org
+#+end_src
+
+Rewrites every heading at level 3 or deeper whose TODO state is DONE/CANCELLED/FAILED into a dated event-log entry (=<stars> YYYY-MM-DD Day @ HH:MM:SS -ZZZZ <text>=), dropping the keyword, priority cookie, and tags, and removing the =CLOSED:= line. Enforces the depth rule that a completed sub-task becomes dated history — a shape interactive org closes and =--archive-done= (level-2 only) leave unapplied. Timestamp comes from each entry's =CLOSED= cookie; heading text kept verbatim; idempotent; a done sub-task with no parseable =CLOSED= is flagged and left alone. Run before archiving so a parent's sub-tasks are already dated when it moves. Capture the output.
+
+To preview without writing: =emacs --batch -q -l .ai/scripts/todo-cleanup.el --convert-subtasks --check todo.org=.
+
+** Step 3: Archive completed work
 
 #+begin_src bash
 emacs --batch -q -l .ai/scripts/todo-cleanup.el --archive-done todo.org
@@ -37,10 +47,11 @@ Moves every level-2 subtree whose TODO state is DONE or CANCELLED out of the "Op
 
 To preview the moves without writing: =emacs --batch -q -l .ai/scripts/todo-cleanup.el --archive-done --check todo.org=.
 
-** Step 3: Summarize
+** Step 4: Summarize
 
-Report to Craig from the two captured outputs:
+Report to Craig from the three captured outputs:
 - Hygiene: how many bogus state-log lines were deleted; any orphan-planning warnings (file:line + heading), or "none".
+- Convert: how many done sub-tasks were rewritten to dated entries (heading + line), any flagged for no =CLOSED= date, or "nothing to convert".
 - Archive: how many subtrees moved and which (heading + line), or "nothing to move" / the skip reason if a section was missing or ambiguous.
 - If the file changed, note that =todo.org= now has an uncommitted edit — review =git diff -- todo.org= and commit it (in this repo's commit style) if it looks right. If nothing changed, say so and stop.
 
@@ -49,7 +60,7 @@ Don't auto-commit. The summary is the review point; Craig decides whether the di
 * Principles
 
 - *Both passes apply, not just preview.* The workflow is invoked because cleanup is wanted. Use the =--check= variants only when Craig asks for a dry run.
-- *Two passes, two invocations.* =--archive-done= is its own mode and does not run the hygiene pass; run both.
+- *Separate modes, separate invocations.* =--convert-subtasks=, =--archive-done=, and the hygiene pass are each their own mode and don't run the others; run all three.
 - *Never auto-commit todo.org.* Surface the diff and let Craig commit it. The cleanup is a working-tree change, fully reversible until committed.
 - *Trust the script.* It's fast and idempotent; if there's nothing to do, it reports zero and exits clean. No pre-checks.