hermes-webui: add Hermex server as loopback compose service on Dankclaw

- compose: hermes-webui runs bootstrap.py --foreground in the agent image,
  shares /home/dank/hermes-data (same uid mapping as the gateway), publishes
  127.0.0.1:8787 only; password from host .env
- planner/remote deployer: hermes-webui is an isolated Dankclaw service
- tests: deployment integrity seam (loopback, auth, volume, healthcheck,
  planner narrowing, deployer dispatch)
- docs: Hermes-WebUI page with the iOS SSH-tunnel access pattern

docs/Dankclaw/Hermes-Dashboard.md

@@ -35,3 +35,7 @@ Open `http://192.168.0.143:9119` in a browser on the LAN. Log in with the config
 - The dashboard and the gateway share one data volume. A config change made in the dashboard takes effect when the gateway restarts.
 - If the shared password is reused elsewhere, treat it as exposed. Rotate it and regenerate the hash.
 - `--skip-build` uses the prebuilt web assets in the image. Do not remove it unless the assets are rebuilt.
+
+## See Also
+
+- [[Hermes-WebUI]] — the phone-facing API server (Hermex)