feat(a2a): CEO can DM the Auditor and PR reviewers (#623)

* feat(a2a): CEO can DM the Auditor and PR reviewers

A mid-flight PR reviewer or Auditor that's stuck was unreachable — the CEO
had no way to DM them. Both roles now carry dm/read_a2a, so the CEO can open
a 1:1 and they can reply in-thread through the existing CEO-reply path.

Scoped deliberately: the Auditor stays a silent observer to its peers — it
gains no peer-initiation surface (can_a2a_direct routes it through
_check_auditor_a2a, which refuses every initiation target; it can only reply
inside a CEO-opened DM). PR reviewers keep their owning-PM scope. Intake and
Secretary stay excluded — they have their own dedicated chat pages.

NO_COMMS_ROLES drops to {prompter, secretary}; the panel's EXCLUDE_NON_DM_ROLES
matches. KB/docs updated so the 'auditor/pr_reviewer have no dm' claim isn't
left stale.

* test(a2a): smoke guard checks _NO_COMMS_ROLES, not a hardcoded 'auditor'

The dm() runtime guard no longer names the auditor (it now carries dm to
reply to the CEO); it refuses the canonical _NO_COMMS_ROLES set. Assert on
that set so the smoke test tracks the guard, not a stale role name.

* chore(foundation): regenerate verb tables for auditor/pr_reviewer dm+read_a2a

---------

Co-authored-by: Renn F <rennf93@users.noreply.github.com>

docs/rag/architecture/tool-permissions.md

@@ -89,7 +89,7 @@ Both share the same flow verbs and read-only git (none), but their content verbs
 
 **Flow verbs:** `triage`, `i_am_idle`  (read-only)
 
-**Content verbs:** `note` (scope=reflect), `evidence`  (no `dm` — Auditor observes silently)
+**Content verbs:** `note` (scope=reflect), `evidence`, `dm`, `read_a2a` (dm/read_a2a exist only so it can reply in-thread to a CEO-opened DM — it never initiates to a peer, so it still observes silently)
 
 **Read-only git:** none.
 
@@ -97,7 +97,7 @@ Both share the same flow verbs and read-only git (none), but their content verbs
 
 **Flow verbs:** `give_me_work`, `claim_pr_review`, `post_pr_review` (inbound external/fork + internal PRs), `claim_gate_review`, `pr_pass`, `pr_fail` (in-path assembled-PR gate), `unclaim`, `i_am_idle`  (read-only)
 
-**Content verbs:** `note`, `evidence`, plus notification reads (`notify_list`, `notify_get`) — no `dm`: the change-request is posted server-side on the PR itself.
+**Content verbs:** `note`, `evidence`, `dm`, `read_a2a`, plus notification reads (`notify_list`, `notify_get`) — the change-request itself is still posted server-side on the PR; `dm`/`read_a2a` exist so it can reply in-thread to a CEO-opened DM, and its only INITIATION target is its owning cell_pm/main_pm (the in-path gate verdict).
 
 **Read-only git:** none.