chore(task-board): mothball it; superseded by the High Seat and ledger

Operator ruling 2026-09-24. On ana-docker the stack is `docker compose
down`: the container is removed and port 7878 is closed. Kept for revival:
- the data dir /opt/docker/conf/task-board/data (tasks.db, last written
  2026-09-11)
- the task-board:local image
- stacks/task-board/ and the host's compose + .env

The Uptime Kuma monitor (id 3) was deleted before the stop so it could
not page, and its row is removed from monitors.yaml. Homepage drops the
card on its own, since it reads the container's labels.

Hooks: the container log showed no hook POSTs in 30 days. The only
traffic was open browser tabs holding /events, and the plugin was already
uninstalled on nh3-dev. Removed the paragraph that told sessions to call
task_* tools (CLAUDE.md, and the fork-fleet.sh template that seeds new
repos), the vestigial TASK_BOARD_SESSION env in .claude/settings.json, and
the listings in README and FLEETTOOLS.

CLAUDE.md

@@ -201,22 +201,12 @@ It deliberately has **no file transfer and no idempotency**; that is elway's hal
   completes, so the completion marker never arrives. A pipe makes stdout a non-tty
   and sudo skips the PTY. Not yet fixed in our fork.
 
-**Task visibility via task-board.** If the Claude Code session has
-the `task-board` plugin enabled (installed from
-`git@gitea.phasefinal.com:vh/task-board.git`), a card at
-`http://10.250.50.70:7878/` tracks work in progress. Hooks flip the
-card on turn boundaries automatically; call `task_start` /
-`task_update` / `task_wait` / `task_complete` MCP tools to set the
-activity subheader and post meaningful log entries.
-
-When you launch a `Bash` tool with `run_in_background: true` (or any
-long-running shell / monitor / poll loop), call `task_set_shells`
-with one short description per active background shell — and call it
-again with the updated list (or `[]`) when one completes. The board
-flips a waiting card to **orange** while the list is non-empty so the
-user can tell at a glance the session is parked on background work,
-not stalled on them. Hooks have no way to enumerate the bg-task list
-externally, so this is on the assistant.
+**task-board is MOTHBALLED (2026-09-24, Prime).** It has been superseded by the
+High Seat (SVOS, `http://10.100.10.50:8770`) and ledger. The container on
+ana-docker is stopped and removed. Its data (`/opt/docker/conf/task-board/data`),
+the `task-board:local` image and `stacks/task-board/` are kept, so it can come
+back with one `docker compose up -d`. Do not call `task_*` MCP tools or wire
+its hooks into new sessions.
 
 ## Model quantization