feat: no-answer retry, agent status machine, escalation events/timeline (ТЗ §13-15,22,25-27,37, AC-08,16-19)

Phase 2 of the L1->L2 routing engine (Phase 1: MR!4).

- ami_loop() now also captures native AMI DialEnd/Hangup frames (not
  only UserEvent), needed to detect that an escalated agent did not
  answer. No dialplan change required - Redirect already routes the
  client channel into an existing Dial()-based transfer context, so
  Asterisk emits these events on its own; the listener just wasn't
  reading them before.
- retry_escalation_no_answer(): on NOANSWER/BUSY/CANCEL/CHANUNAVAIL/
  CONGESTION, releases the non-answering agent, excludes it, and
  reserves+redirects to the next available agent via the routing
  engine's existing exclude_agent_ids support. Exhausted pool marks
  the escalation failed and leaves the call with the AI instead of
  dropping the client (ТЗ §32).
- Agent status now actually moves through
  RESERVED -> RINGING -> TALKING -> AFTER_CALL_WORK -> AVAILABLE
  instead of staying stuck on RESERVED for the whole call; a new
  acw_sweep_loop background thread (same pattern as the existing
  failed_retry_loop) times out AFTER_CALL_WORK back to AVAILABLE.
- escalations gains attempt_count/real_agent_id/attempted_agent_ids_json
  (migration 0033); fixes a latent bug where assigned_agent_id stored
  the SIP extension instead of the real agent_id despite routing-service
  already returning it in RoutingAgentReserveOut.
- Every transition now records an interaction timeline entry and
  publishes the ТЗ §25 event catalog (AgentReserved/AgentRinging/
  AgentNoAnswer/AgentConnected/TransferCompleted/TransferFailed)
  through the existing emit_voice_event/EventOutboxRow idempotent path.

Not in this MR (see plan): SLA config, Callback, L3 (needs real
technical agents from the business), metrics.

contracts/events/agent.connected.json

@@ -0,0 +1,13 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "title": "AgentConnected",
+  "type": "object",
+  "required": ["event", "call_id", "escalation_id", "agent_id", "created_at"],
+  "properties": {
+    "event": { "const": "AgentConnected" },
+    "call_id": { "type": "string" },
+    "escalation_id": { "type": "string" },
+    "agent_id": { "type": "string" },
+    "created_at": { "type": "string", "format": "date-time" }
+  }
+}

contracts/events/agent.no_answer.json

@@ -0,0 +1,15 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "title": "AgentNoAnswer",
+  "type": "object",
+  "required": ["event", "call_id", "escalation_id", "agent_id", "dial_outcome", "created_at"],
+  "properties": {
+    "event": { "const": "AgentNoAnswer" },
+    "call_id": { "type": "string" },
+    "escalation_id": { "type": "string" },
+    "agent_id": { "type": ["string", "null"] },
+    "dial_outcome": { "type": "string" },
+    "attempt_count": { "type": "integer" },
+    "created_at": { "type": "string", "format": "date-time" }
+  }
+}

contracts/events/agent.reserved.json

@@ -0,0 +1,18 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "title": "AgentReserved",
+  "type": "object",
+  "required": ["event", "call_id", "escalation_id", "agent_id", "created_at"],
+  "properties": {
+    "event": { "const": "AgentReserved" },
+    "call_id": { "type": "string" },
+    "escalation_id": { "type": "string" },
+    "agent_id": { "type": "string" },
+    "tenant_id": { "type": ["string", "null"] },
+    "from_level": { "type": "string" },
+    "to_level": { "type": "string" },
+    "reason_code": { "type": "string" },
+    "attempt_count": { "type": "integer" },
+    "created_at": { "type": "string", "format": "date-time" }
+  }
+}

contracts/events/agent.ringing.json

@@ -0,0 +1,13 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "title": "AgentRinging",
+  "type": "object",
+  "required": ["event", "call_id", "escalation_id", "agent_id", "created_at"],
+  "properties": {
+    "event": { "const": "AgentRinging" },
+    "call_id": { "type": "string" },
+    "escalation_id": { "type": "string" },
+    "agent_id": { "type": "string" },
+    "created_at": { "type": "string", "format": "date-time" }
+  }
+}

contracts/events/transfer.completed.json

@@ -0,0 +1,13 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "title": "TransferCompleted",
+  "type": "object",
+  "required": ["event", "call_id", "escalation_id", "agent_id", "created_at"],
+  "properties": {
+    "event": { "const": "TransferCompleted" },
+    "call_id": { "type": "string" },
+    "escalation_id": { "type": "string" },
+    "agent_id": { "type": "string" },
+    "created_at": { "type": "string", "format": "date-time" }
+  }
+}

contracts/events/transfer.failed.json

@@ -0,0 +1,15 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "title": "TransferFailed",
+  "type": "object",
+  "required": ["event", "call_id", "created_at"],
+  "properties": {
+    "event": { "const": "TransferFailed" },
+    "call_id": { "type": "string" },
+    "escalation_id": { "type": ["string", "null"] },
+    "agent_id": { "type": ["string", "null"] },
+    "reason": { "type": ["string", "null"] },
+    "error": { "type": ["string", "null"] },
+    "created_at": { "type": "string", "format": "date-time" }
+  }
+}