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/code-editor/_index.md

@@ -0,0 +1,5 @@
+---
+theme: code-editor
+heading: "Code editor"
+kind: theme
+---

todo/code-editor/the-owner-wants-to-go-deeper-here-ideas.md

@@ -0,0 +1,36 @@
+---
+id: code-editor/the-owner-wants-to-go-deeper-here-ideas
+title: "The owner wants to go deeper here — ideas pending (noted 2026-08-15)"
+theme: code-editor
+status: open
+created: 2026-08-15
+date_source: stated
+order: 1
+---
+
+**The owner wants to go deeper here — ideas pending (noted 2026-08-15).** Raised right after the file
+browser gained its first links into `/code-editor`. Do this after the file-browser test pass.
+
+What is worth knowing before starting, all established on 2026-08-15:
+
+**It has been effectively invisible for six months.** The app landed 2026-02-21 (`9e9acd96`), the
+screen 2026-02-17, and `1fa3a659` on 2026-07-25 is titled "**restore** the code editor screen" — so
+it was dropped and brought back at least once. It IS in `CORE_DOCK_ITEMS` as "Editor", but
+`DEFAULT_DOCK_PATHS` is `['/', '/files', '/terminal', '/dashboards', '/chat']` and the owner's own
+`dock_configs` row does not list it either. Until today the only way in was typing the URL.
+
+**So it has no users, and that is the risk.** A surface nobody reached for six months is where things
+rot quietly. Nothing about the editor itself has been verified — whether saving works, how the file
+tree behaves, what closing the last tab does, what an unsaved-changes navigation does. Only the
+plumbing was checked: `?file=` is read (`EDITOR_FILE_PARAM`), `/code-editor` renders with `urlState`,
+and `CodeEditor.tsx:60-76` fetches a path that arrives in the URL rather than only matching already
+open tabs.
+
+**One bug of exactly this kind was already found and fixed** in the FileViewer's editor on the same
+day: the Edit toggle was gated on `content` rather than `content !== null`, so an empty file — the
+one "New file" produces — could not be edited at all. Assume siblings.
+
+**Open question, deliberately not decided:** `Open in editor` in the file browser's row menu still
+navigates to `/code-editor`, which is the last action that leaves the browser. Editing now happens
+in place via double-click → the viewer's pane. Either `/code-editor` earns its keep as a genuinely
+different tool (tree, tabs, multi-file) or that menu item should go.