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.

services/shared/sql_models.py

@@ -846,6 +846,9 @@ class EscalationRow(Base):
     summary: Mapped[str | None] = mapped_column(Text, nullable=True)
     status: Mapped[str] = mapped_column(String(32), index=True, default="requested")
     assigned_agent_id: Mapped[str | None] = mapped_column(String(64), nullable=True, index=True)
+    real_agent_id: Mapped[str | None] = mapped_column(String(64), nullable=True, index=True)
+    attempted_agent_ids_json: Mapped[str] = mapped_column(Text, default="[]")
+    attempt_count: Mapped[int] = mapped_column(Integer, default=0)
     requested_at: Mapped[str] = mapped_column(String(64), index=True)
     connected_at: Mapped[str | None] = mapped_column(String(64), nullable=True)
     completed_at: Mapped[str | None] = mapped_column(String(64), nullable=True)