Define Hermes router as named authenticated provider

platform/hermes/config.yaml

@@ -2,12 +2,25 @@ _config_version: 38
 
 model:
   default: "qwen-medium"
-  provider: "custom"
+  provider: "custom:router"
   base_url: "http://router:8081/v1"
   api_key: "${ROUTER_API_KEY}"
   context_length: 160000
   api_mode: "chat_completions"
 
+# A named provider is required by current Hermes releases.  A bare `custom`
+# endpoint is canonicalized to a host-derived identity and can lose its key
+# association in resumed sessions.  The stable identity below always resolves
+# its credential from the container environment.
+providers:
+  router:
+    name: "Athena Profile Router"
+    api: "http://router:8081/v1"
+    key_env: "ROUTER_API_KEY"
+    transport: "chat_completions"
+    default_model: "qwen-medium"
+    discover_models: true
+
 # Commands run in an isolated, persistent workspace. Host and Unraid changes
 # use the audited operator/MUA MCPs instead of a Docker socket or host mount.
 terminal: