docs: note SSH capability tracks executor initialization

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Signed-off-by: Noppanat Wadlom <noppanat.wad@gmail.com>

Author: kaiitunnz

src/worker/README.md

@@ -119,10 +119,11 @@ The SSH session container is labelled with `flowmesh.ssh.task_id` and
 `flowmesh.ssh.worker_id` so the server can clean it up if the worker
 container is stopped externally.
 
-At startup the worker probes Docker reachability and advertises its `ssh`
-capability accordingly, so the dispatcher selects it for SSH tasks only when
-Docker is actually usable. (The supervisor mounts the Docker socket only when
-SSH is enabled for the node; see `ENABLE_SSH_BY_DEFAULT` below.)
+At startup the worker initializes the SSH executor only if the Docker daemon is
+reachable, and advertises its `ssh` capability accordingly; the dispatcher then
+selects it for SSH tasks only when it can actually run them. (The supervisor
+mounts the Docker socket only when SSH is enabled for the node; see
+`ENABLE_SSH_BY_DEFAULT` below.)
 
 Relevant env vars for SSH tasks: