Add fleet control: service configs, replica floors, monitor, pause/restart

Central fleet.json sets min/max copies. Tree-node keepFloor respawns
until three healthy unpaused replicas remain. CLI and loopback UI
pause, resume, stop, and restart instances that fail health checks.

docs/02-architecture/fleet.md

@@ -0,0 +1,21 @@
+# Fleet: replica floors, monitor, pause, restart
+
+Runtime copies of middleware workers, WORM archives, and **tree nodes** are declared in `packages/verae-fleet/fleet.json` (how many) and `packages/verae-fleet/services/*.json` (how each one runs).
+
+```text
+operator  --HTTP 127.0.0.1:3850-->  fleet control
+                                      | spawn workers with /health
+          tree-node min=3 keepFloor   |
+          archive-worm min=3          |
+          paused ≠ available          |
+          unhealthy → restart         v
+                               replicas on loopback health ports
+```
+
+- **list** — `node src/cli.js list`
+- **monitor** — `serve` probes `/health` and reconciles
+- **restart** — crash or 503 → same instance id respawned
+- **pause / off** — pause does not count toward `min`; keepFloor starts another tree-node. `stop` on a service disables it.
+- **tree-node floor** — `fleet.json` `tree-node.min` (default 3). Do not drop this without changing the spec; bulk-summary leaf queries need several bloom-filtered nodes.
+
+Zapier cloud is not spawned. NATS is monitored, not bound publicly.