feat(po): drop periodic fleet sweep — operator-driven, recover-if-dead only

The PO's job is to manage projects on request, not watch them live. Remove the
hourly wake/sweep entirely:

- agents.toml: watch="heal" (recover-if-dead), no `wake` field
- prompts/supervise.md: deleted
- prompts/orchestrator.md, README.md, docs/bootstrap.md, docs/manage-projects.md:
  drop sweep/wake references; document operator-driven, no periodic sweep

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docs/bootstrap.md

@@ -36,13 +36,13 @@ fleet pieces.
 
 3. **Write the harness config** — `agents.toml` declaring the PO's own agent(s). A single
    `kind = "persistent"` `project-orchestrator` agent (backend `claude`) is enough to start; its
-   startup prompt is `prompts/orchestrator.md` and it gets an hourly `wake` →
-   `prompts/supervise.md`. (You can scaffold a starter with `python3 engine/agents.py init .` and
-   then edit it, or copy this repo's `agents.toml`.)
+   startup prompt is `prompts/orchestrator.md`, with `watch = "heal"` (recover-if-dead) and **no**
+   `wake` — the PO is operator-driven, not woken on a timer. (You can scaffold a starter with
+   `python3 engine/agents.py init .` and then edit it, or copy this repo's `agents.toml`.)
 
 4. **Add the fleet pieces** (what makes this project a PO):
    - `fleet.toml` — the registry (schema: `docs/fleet-registry.md`), starting empty or with a sample.
-   - `prompts/orchestrator.md` + `prompts/supervise.md` — the PO agent's role and periodic sweep.
+   - `prompts/orchestrator.md` — the PO agent's role / startup prompt.
    - `scripts/` — `fleet.py` (read/validate the registry) and `create/start/stop/update-project.sh`.
    - `docs/` — these runbooks.