Add isolated SIP call tool, optional debug capture and split interface schemas

deploys/cell/README.md

@@ -51,7 +51,13 @@ reports its applied revision. Local Mock fixtures do not prove real services.
 
 Before every real outbound attempt, the operator must obtain a fresh user
 confirmation in the current conversation that names the SIP channel, raw target
-number and capture plan. Task and trunk schedules and quotas come from the
+number and, when `agent --debug/-D` is enabled, capture plan. External tcpdump
+and the capture-first wrapper are opt-in debugging tools, not normal-production
+requirements. Debug mode still fails closed on missing/invalid capture evidence;
+the HEP SIP-response mirror remains independent and required for that response
+reporting path. The standalone no-AI line test is documented in
+[`cmd/sip-call/README.md`](../../cmd/sip-call/README.md).
+Task and trunk schedules and quotas come from the
 verified SaaS configuration snapshot; the local host has no separate fixed
 hour or daily-attempt limit. Missing or contradictory schedules fail closed;
 do not wait, retry, delay or switch trunks. A prior confirmation does not