Move the to-do list from NOTES.md to a kandown board

Each note is a task in tasks/ with the owner's words under ## Context; the
board rules are in .kandown/kandown_work.md and docs/kandown.md explains how
kandown works here.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/DESIGN.md

@@ -18,7 +18,7 @@ decides something new, add it under "Decisions" with the date.
 - **Copy and paste of builds.** Pasting places ghosts that the bot builds from the bag.
 - **Tool upgrades are earned in a satisfying, not tedious way**, not bought with arbitrary
   credits. So far that means casting them: a drill bit in a Bit mold, a bigger bag in a Tank mold.
-  The owner wants the whole upgrade system redesigned (see NOTES.md).
+  The owner wants the whole upgrade system redesigned (task t14).
 - **A hovering bot that flies freely.** A limited bag that can be upgraded.
 - **An economy instead of a rocket or other final goal.**
   - Sell materials at the trade dock; refined goods and alloys pay more.
@@ -165,7 +165,8 @@ above, including:
   refiners until none is left. The owner's reason: it is less profitable than making glass, so
   players will do it only when they need more ore rather than more money.
 - The project moved from a claude.ai artifact to local development with coding agents. It is
-  built from small files, with `NOTES.md` as the owner's to-do inbox.
+  built from small files, with `NOTES.md` as the owner's to-do inbox (since 2026-10-24, a
+  kandown board in `tasks/`).
 - **Replace is held G, not Ctrl.** The owner hit the browser's Ctrl+W (close tab) and Ctrl+D
   (bookmark) while replacing and flying with WASD, and the game ignored WASD while Ctrl was held.
 
@@ -200,9 +201,14 @@ above, including:
   list loads, renames and deletes them, and a new or imported world never overwrites another. An
   old single save becomes 'World 1'. The owner asked for multiple saves.
 
+**2026-10-24:**
+- **The to-do list is a kandown board.** `NOTES.md` became one task file per note in
+  `tasks/` (Todo for tasks, Backlog for discussions and ideas, Review for "done, please check").
+  The owner wanted a task tool built for AI agents.
+
 ## Ideas not built yet
 
 - **Concrete**, as a stronger wall material from rubble.
 - **Upgrade ideas for the drill**: an amplifier, a tuning fork, harmonics. Also a Grav pick
   upgrade tool and mining charges. See `docs/systems/dig-tools.md`.
-- The owner's ideas for later are in the "Future features and ideas" section of `NOTES.md`.
+- The owner's ideas for later are tasks tagged `idea` in the Backlog of the task board.

docs/PROJECT_MAP.md

@@ -9,7 +9,7 @@ top part by hand when the structure changes.
 
 ```
 AGENTS.md, CLAUDE.md  instructions for coding agents
-NOTES.md              the owner's to-do inbox
+tasks/, .kandown/     the owner's to-do list: a kandown board (docs/kandown.md)
 build.py              joins src/ into dist/index.html (one self-contained page)
 src/manifest.json     the build order: simulation files, then browser files
 src/shell.html        page markup (HUD, menus, dialogs); CSS and JS are put in at the markers

docs/agent-log.md

@@ -4,6 +4,32 @@ What agents have done, newest first. Add an entry for every piece of work: the d
 note or request it was for, what changed, the files touched, the tests run, and anything left
 open or not verified. Keep each entry short; the git history has the details.
 
+## 2026-10-24: the to-do list moved from NOTES.md to a kandown board (Claude Code)
+
+Request: initialize kandown (https://kandown.dev, 0.52.0) for the project, move all the notes
+into it, and document how it works.
+
+- Practised first in a scratch folder: `init --no-open` starts no daemon and makes no sample tasks
+  when `tasks/` exists; `create` prints only the id and names the file `<id>_<slug>.md`; a
+  multi-line `report: |` block is read (checked in kandown's parser) and `doctor` accepts it;
+  `list --json` doesn't include `report`; project instructions in `.kandown/kandown_work.md`
+  appear in `kandown work` (~1,100 tokens).
+- A mistake on the way: `kandown init --help` ran `init` in the vault (it ignores `--help`) and
+  started a daemon there. Stopped it, and removed the vault's earlier kandown test files as the
+  owner asked. `docs/kandown.md` warns about it.
+- `kandown init --no-open` in the repo. `.kandown/kandown.json`: default columns, Review's
+  instructions say only the owner moves work to Done, tags and priority shown. `.gitignore`:
+  `.kandown/kandown.html` (6.5 MB, regenerated).
+- 14 notes became tasks t1-t14 (Todo: 6 tasks; Backlog: 5 tagged `discussion`, 3 tagged
+  `idea`), each with the owner's note word for word under `## Context` (checked by script: 14 of
+  14). `kandown doctor` is clean.
+- `.kandown/kandown_work.md` holds the board rules (from AGENTS.md's old NOTES section);
+  `docs/kandown.md` explains how kandown works here. `AGENTS.md` (session start, a new "Working
+  from the task board" section linking both), `CLAUDE.md`, `README.md`, `docs/PROJECT_MAP.md`,
+  `docs/DESIGN.md` (decision). `NOTES.md` removed.
+- `kandown list` and `kandown doctor` checked inside Codex's sandbox: they work.
+- Open: the web board (`kandown`) wasn't opened here; the owner uses it.
+
 ## 2026-10-24: several worlds, with a Worlds list (Claude Code, with Codex)
 
 Note: "support multiple saves". The owner chose a world list.