feat(homepage): wire ana-ml2 back into discovery via socat proxy on ana-docker

ana-ml2 is up but not reachable cross-site from ESH (return-route gap on ana-ml2,
no SSH access to fix it). New stacks/ana-ml2-proxy: a pinned alpine/socat relay on
ana-docker (host net) exposing 10.250.50.70:2354 -> ana-ml2 10.250.50.54:2375.
Homepage docker.yaml ana-ml2-docker re-enabled pointed at the proxy. Verified:
esh-docker-vm reaches ana-ml2's docker (29.3.1) through it; /api/services returns
in 0s with 111 services; ana-ml2's inference seats (gen, coder, embed, rerank,
reward, image-bench, dockge) render. Reversible: point back at 10.250.50.54:2375
and compose-down the proxy once ana-ml2 routes to ESH.

stacks/homepage/conf/docker.yaml

@@ -17,14 +17,15 @@ nh3-pfi-docker:
   host: 10.100.50.40
   port: 2375
 
-# ana-ml2-docker DISABLED 2026-09-07: 10.250.50.54:2375 is not reachable from
-# esh-docker-vm (docker API not exposed/listening — ana-docker 10.250.50.70:2375
-# on the SAME subnet IS reachable, so this is host-specific, not routing). A dead
-# host here hangs the entire /api/services aggregation until its TCP connect times
-# out. Re-enable once ana-ml2 exposes the docker API and it is reachable from ESH.
-# ana-ml2-docker:
-#   host: 10.250.50.54
-#   port: 2375
+# ana-ml2-docker — reached via a socat proxy on ana-docker (stacks/ana-ml2-proxy).
+# ana-ml2's own :2375 is up but not reachable cross-site from ESH (a return-route
+# gap on ana-ml2 itself; no SSH access from the ops seats to fix its routing).
+# ana-docker is on the same Anaheim subnet and IS reachable from ESH, so it
+# relays 10.250.50.70:2354 -> 10.250.50.54:2375. Point back at 10.250.50.54:2375
+# and `docker compose down` the proxy once ana-ml2 has a return route to ESH.
+ana-ml2-docker:
+  host: 10.250.50.70
+  port: 2354
 
 # irv-ml1 — moved 10.100.79.3 -> 10.6.110.50 on 2026-09-06 (headscale cutover;
 # the old wg0 tunnel IP is dormant and no longer answers). Reachable from