feat: pass --name to local claude spawns so workers carry their session names as peer names

Version-gated fail-closed at 2.1.224 (the cross-session-messaging release,
flag presence verified against that binary): an unknown or older CLI yields
a spawn command byte-identical to before, because claude aborts startup on
an unknown option and that would kill every session spawn. The value is
allowlist-sanitized ahead of the double-quoted interpolation, and only the
local command carries the flag; docker/remote builders never see it since
their CLI is not the probed binary. Verified E2E on an isolated instance:
cmdline shows --name, ListAgents lists the session name, replies arrive
tagged from-name.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

skills/codeman/reference/messaging.md

@@ -61,6 +61,17 @@ your quick-start's `sessionId`. The peer NAME (`msgtest-worker-cf`) is assigned
 Claude Code, derived from the case directory's folder name plus a suffix Codeman does
 not control: never guess it from the case name, read it from the listing.
 
+From Codeman 1.16 a LOCAL claude spawn passes `--name <session name>` when the local
+CLI is 2.1.224+, so a worker's peer name usually IS its Codeman session name
+(verified live: quick-start with `sessionName: "w9-msgtest"` listed as `w9-msgtest`,
+and its messages arrive tagged `from-name="w9-msgtest"`; a derived-name worker's
+messages carry no `from-name`). Name your workers: a quick-start WITHOUT
+`sessionName` leaves the Codeman name empty, so there is nothing to pass and the
+peer name stays derived. The flag is fail-closed (older/unknown CLI omits it) and
+allowlist-sanitized (a name of only unsafe characters is dropped), and docker/remote
+spawns never carry it, which is why the `tmux` column stays the canonical join key
+rather than the name.
+
 Scriptable probe + name lookup, against the registry Claude Code maintains (one JSON
 object per process in `~/.claude/sessions/<pid>.json`):