ops: tuwunel loads appservice registrations via TUWUNEL_APPSERVICE_DIR

Inline [appservice.*] tables drop the namespaces field (registration then
fails M_EXCLUSIVE for every AS user). The env var points tuwunel at the
/appservices mount (telegram + hub YAMLs, both with namespaces).

infra/occupymedia/docker-compose.chat.yml

@@ -9,6 +9,10 @@ services:
   conduwuit:
     image: tuwunel:v1.9.4
     command: ["-c", "/etc/tuwunel/tuwunel.toml"]
+    environment:
+      # Appservice registrations (telegram + hub) load from this directory; the
+      # hub AS owns the exclusive hub_* namespace for in-app Chat sign-in.
+      TUWUNEL_APPSERVICE_DIR: /appservices
     volumes:
       - tuwunel_data:/var/lib/conduwuit
       - /opt/occupymedia/tuwunel.toml:/etc/tuwunel/tuwunel.toml:ro