# L1 -> L2 Routing Engine (Phase 1)

Implements a real Agent Pool + Routing Engine for voice escalation from
Voice AI (L1) to live L2 operators, replacing the previous static
single-extension redirect target.

## What changed

- `agents` table (`services/routing_service/engine.py`): agents are rows with
  `level`, `tenant_ids`, `skills`, `status`, `max_concurrent_calls`, `enabled` -
  not a hardcoded list. Selection filters by level/tenant/skills and picks the
  longest-idle, least-loaded match. Reservation is an atomic
  `UPDATE ... WHERE status='AVAILABLE'` (rowcount-checked), so two concurrent
  calls can never reserve the same agent.
- `escalations` table: one row per escalation attempt (`from_level`,
  `to_level`, `reason_code`, `required_skills`, `priority`, `status`).
- `routing_rules` table: seeded data (not code) describing which
  level-to-level transitions are allowed; `L3` and multi-tenant rules can be
  added later without code changes.
- `asterisk_call_links` gained `tenant_id`, `current_level`,
  `required_skills_json`, `priority`.
- `POST /asterisk/live-calls/{call_id}/escalations` (asterisk-bridge-service):
  explicit escalation entrypoint. `voice_ai.request_handoff` (used by the AI
  runtime) now also uses the Agent Pool automatically for any `queue_code`
  configured in `ASTERISK_QUEUE_LEVEL_MAP_JSON`; every other queue_code keeps
  the old static `ASTERISK_TRANSFER_TARGET_MAP_JSON` behavior unchanged.
- `routing-service` gained `/agents` CRUD + `/internal/routing/reserve-agent`
  and `/internal/routing/release-agent`, called by asterisk-bridge-service
  the same way it already calls interaction-service/ai-voice-runtime-service
  (bridge-issued bearer token, `ROUTING_SERVICE_URL`).
- Agent is released back to `AVAILABLE` when the call ends
  (`process_call_ended` in `bridge_processing.py`), which also closes the
  matching open `escalations` row.

## Config for a given DID/queue

```
ASTERISK_QUEUE_LEVEL_MAP_JSON={"<queue_code>":{"level":"L2","tenant_id":"konturai"}}
```

Any `queue_code` not listed here keeps behaving exactly as before (static
`ASTERISK_TRANSFER_TARGET_MAP_JSON` redirect) - this is additive, not a
replacement of the legacy mechanism.

Seed `agents` rows via `POST /agents` (admin/supervisor). Level `L2`,
`extension` must match a real SIP endpoint (currently only `2001`/`2002`
exist on the telecom server).

## Known gap - no-answer retry

Today the Routing Engine picks and reserves one agent and issues a single AMI
`Redirect` to their extension; if that extension does not answer, the caller
currently depends on whatever the dialplan does at that extension (unchanged
from before this change). Automatic "agent didn't answer -> release and pick
next" requires either:

1. A small dialplan addition at the target extension's context: `Dial` with a
   fixed timeout and, on failure, a `UserEvent` back into the bridge (mirrors
   the existing `MVPCCAIFallbackToHuman` pattern) so `asterisk_bridge_service`
   can call `/internal/routing/reserve-agent` again with the failed agent in
   `exclude_agent_ids`, or
2. Switching from `Redirect` to AMI `Originate` with `Timeout` and reacting to
   `OriginateResponse`.

Left out of Phase 1 deliberately: changing dialplan behavior without full
visibility into what a given extension's context currently does on no-answer
risks silently dropping a live customer call. Needs a follow-up MR with an
explicit, reviewed dialplan change.

## Not in Phase 1

- L3 (technical specialists) - `agents.level='L3'` and `routing_rules` already
  support it; enabling it is a data-only follow-up once real L3 agents exist.
- SLA config / callback (ТЗ sections 20-21).
- Metrics (ТЗ section 38).
