Drop the Traefik-level basic auth layer — keep only Hermes's own login

By request: one auth layer, not two. Note this isn't really removing a
layer I added on top of nothing — Hermes's own gate is mandatory and
can't be disabled while the dashboard is reachable through a separate
Traefik container (it fails closed at startup on any non-loopback bind
without a configured auth provider). The only thing actually optional
was the Traefik-level middleware, so that's what comes out; Traefik now
just does TLS termination + routing.

.env.example

@@ -39,16 +39,13 @@ HERMES_MATRIX_ACCESS_TOKEN=
 HERMES_API_SERVER_KEY=
 
 # --- hermes web dashboard (hermes.apps.williamturner.eu) ---
-# Two independent auth layers: Hermes's own login (basic auth — its docs call this
-# "not suitable for direct public-internet exposure" alone) plus a Traefik-level basic
-# auth gate in front of it. Both required, different credentials recommended.
+# Hermes's own login gate — mandatory once its dashboard is bound non-loopback (needed
+# for Traefik, a separate container, to reach it at all), so this can't be turned off
+# while the dashboard is reachable through Traefik.
 HERMES_DASHBOARD_USERNAME=william
 HERMES_DASHBOARD_PASSWORD=
 # 32+ random bytes — `openssl rand -base64 32`
 HERMES_DASHBOARD_SECRET=
-# htpasswd-format "user:hash" for Traefik's basicauth middleware. Generate with:
-#   python3 -c "import crypt; print('someuser:' + crypt.crypt('somepassword', crypt.mksalt(crypt.METHOD_SHA512)))"
-TRAEFIK_HERMES_AUTH_HASH=
 
 # --- portainer (GitOps redeploy) ---
 PORTAINER_STACK_WEBHOOK_URL=