Add Management Service and CLI components (design docs)

New components 18-19: ManagementService (Akka.NET actor on Central exposing
all admin operations via ClusterClientReceptionist) and CLI (console app using
ClusterClient for scripting). Updated HighLevelReqs, CLAUDE.md, README,
Component-Host, Component-Communication, Component-Security.

README.md

@@ -51,6 +51,8 @@ This document serves as the master index for the SCADA system design. The system
 | 15 | Host | [Component-Host.md](Component-Host.md) | Single deployable binary, role-based component registration, per-component config binding (Options pattern), readiness gating, dead letter monitoring, Akka.NET bootstrap, ASP.NET Core hosting for central. |
 | 16 | Commons | [Component-Commons.md](Component-Commons.md) | Namespace/folder convention (Types/Interfaces/Entities/Messages), shared data types, POCOs, repository interfaces, message contracts with additive-only versioning, UTC timestamp convention. |
 | 17 | Configuration Database | [Component-ConfigurationDatabase.md](Component-ConfigurationDatabase.md) | EF Core data access, per-component repositories, unit-of-work, optimistic concurrency on deployment status, audit logging (IAuditService), migration management. |
+| 18 | Management Service | [Component-ManagementService.md](Component-ManagementService.md) | Akka.NET ManagementActor on central, ClusterClientReceptionist registration, programmatic access to all admin operations, CLI interface. |
+| 19 | CLI | [Component-CLI.md](Component-CLI.md) | Standalone command-line tool, System.CommandLine, Akka.NET ClusterClient transport, LDAP auth, JSON/table output, mirrors all Management Service operations. |
 
 ### Reference Documentation
 
@@ -81,6 +83,10 @@ This document serves as the master index for the SCADA system design. The system
 │  │ Inbound  │  ◄── External Systems (X-API-Key)     │
 │  │ API      │      POST /api/{method}, JSON         │
 │  └──────────┘                                       │
+│  ┌──────────┐                                       │
+│  │ Mgmt     │  ◄── CLI (ClusterClient)              │
+│  │ Service  │      ManagementActor + Receptionist   │
+│  └──────────┘                                       │
 │  ┌───────────────────────────────────┐              │
 │  │    Akka.NET Communication Layer   │              │
 │  │  (correlation IDs, per-pattern    │              │