dockerproxy: pin traefik-manager to .4, add direct TCP monitor for traefik

- Pinned traefik-manager to 172.18.0.4 (was floating in the dynamic pool)
- Added Uptime Kuma monitor id=38 "Traefik Container (direct)" — TCP probe
  at 172.18.0.3:80, decoupled from the routing-layer HTTP probe so a
  Traefik container failure is distinguishable from a routing breakage
- Documented that AutoKuma v2 is silently broken; monitor was created via
  direct SQL insert as a workaround

docs/13-DOCKERPROXY-NETWORK.md

@@ -35,6 +35,7 @@ After recreating, compose-managed containers reconnect via `docker compose up -d
 |----|-----------|
 | .1 | (gateway) |
 | .3 | traefik |
+| .4 | traefik-manager |
 | .6 | dockersocket |
 | .8 | authentik-worker |
 | .9 | authentik |
@@ -89,3 +90,22 @@ On Unraid: `/root/dockerproxy-recreate-2026-05-17/`
 - `network-before.json` — full `docker network inspect` output
 - `state.tsv` — per-container name/static-IP/runtime-IP/status/restart-policy
 - `containers.txt` — sorted container list (32 entries)
+
+## Monitoring
+
+Two Uptime Kuma monitors cover Traefik (since 2026-05-17):
+
+| ID | Name | Type | Target | Purpose |
+|----|------|------|--------|---------|
+| 6 | Traefik Dashboard | http | https://traefik.xtrm-lab.org | End-to-end check (routing + TLS) |
+| 38 | Traefik Container (direct) | port | tcp://172.18.0.3:80 | Direct TCP probe inside dockerproxy — detects "container not running" independently of routing |
+
+Diagnostic combination:
+- id=6 red + id=38 green → Traefik is up but misconfigured/routing-broken
+- both red → Traefik container itself is down
+
+## Known Issue — AutoKuma broken
+
+AutoKuma v2.0.0 logs into Uptime Kuma successfully but silently loops on `getTags` and never scans Docker containers. Suspected `AUTOKUMA_DOCKER=1` (single-underscore v1 syntax) isn't recognised by v2's nested-double-underscore config. Also, the bundled `medaziz11/uptimekuma_restapi:dev` API container is out of date — its `POST /monitors` fails on the now-required `conditions` column.
+
+As a workaround, monitor id=38 was created with a direct `INSERT INTO monitor` on `/mnt/user/appdata/uptimekuma/kuma.db` followed by an UK container restart. The `kuma.traefik_container.*` labels on `traefik-manager` are inert until AutoKuma is fixed but kept in place for that future.