todo: one file per item, grouped by theme, with a generated index

TODO.md had reached 1050 lines and 72 open items across 28 sections, read mostly
on a phone. It is now a directory: todo/<theme>/<item>.md, one card per file, with
frontmatter carrying id, status, created date and order, and the prose body copied
across verbatim. TODO.md becomes a generated index (bun run todo:index).

Dates: where an item's prose stated one it is used; otherwise its old section's;
otherwise 2026-08-20, floored at the day before the split rather than invented.
date_source records which.

Shaped for a two-way Kanban board, filed as todo/tooling — a card is a file, id is
the identity, frontmatter is the machine's half and the body is the owner's.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

todo/background-jobs/_index.md

@@ -0,0 +1,5 @@
+---
+theme: background-jobs
+heading: "Background jobs"
+kind: theme
+---

todo/background-jobs/a-repeating-prompt-on-the-background-job.md

@@ -0,0 +1,18 @@
+---
+id: background-jobs/a-repeating-prompt-on-the-background-job
+title: "A repeating prompt on the background-job starter"
+theme: background-jobs
+status: open
+created: 2026-08-20
+date_source: stated
+order: 1
+---
+
+**A repeating prompt on the background-job starter.** An option beside the existing controls: send
+this agent a message every N minutes or hours. This is the Nudger from 2026-08-20 in the place it
+actually belongs — attached to a job that is already running, rather than a separate schedule
+pointing at a session that may not exist.
+The hard-won part is already written down: `api/chat/nudger.ts` refuses when the session is not
+live, when it is generating, and when any other session is live in the same tree — because "not
+generating" was once treated as permission and started a second agent in a repository another was
+building in. Whatever shape this takes, it inherits those three refusals.