docs(v2): update for gap-closeout — peer-URI discovery, role overlays, release status

docs/ServiceHosting.md

@@ -25,6 +25,16 @@ Galaxy access still uses the separately-installed **mxaccessgw** sidecar (see `d
 
 Single-node dev: `OTOPCUA_ROLES=admin,driver`. Production: typically two admin nodes (HA pair) + N driver nodes.
 
+### Per-role configuration overlays
+
+`Program.cs:33-35` builds a role suffix by joining the parsed roles **alphabetically** with `-` and loads `appsettings.{roleSuffix}.json` as an optional overlay on top of base `appsettings.json`. Three overlays ship in `src/Server/ZB.MOM.WW.OtOpcUa.Host/`:
+
+- `appsettings.admin.json` — admin-only nodes
+- `appsettings.driver.json` — driver-only nodes
+- `appsettings.admin-driver.json` — fused single-node dev / small deployments
+
+All three carry Serilog log-level overrides + `Security:Ldap:DevStubMode = false`. Loading order is **base `appsettings.json` → role overlay (`appsettings.{role}.json`) → environment overlay (`appsettings.{Environment}.json`)** — later layers win. Overlays are optional; the base file boots a node on its own.
+
 ## Akka cluster
 
 The host joins an Akka.NET cluster bound to the address in `appsettings.json::Cluster`: