feat: Add gRPC API Layer - Phase 6 Integration

Added Protobuf definitions and gRPC services for all CQ layers:

Protobuf Files (4):
- configuration.proto: 2 Commands + 3 Queries (5 RPCs)
- clubmembership.proto: 3 Commands + 3 Queries (6 RPCs)
- networkmembership.proto: 3 Commands + 3 Queries (6 RPCs)
- commission.proto: 5 Commands + 4 Queries (9 RPCs)

gRPC Services (4):
- ConfigurationService: SetConfigurationValue, Deactivate, GetByKey, GetAll, GetHistory
- ClubMembershipService: Activate, Deactivate, AssignFeature, Get, GetAll, GetHistory
- NetworkMembershipService: Join, Move, Remove, GetPosition, GetTree, GetHistory
- CommissionService: Calculate+Process+Withdraw (5 commands), Get queries (4)

Features:
- HTTP transcoding enabled via google.api.http annotations
- Auto-registration via ConfigureGrpcEndpoints
- MetaData pagination support
- Request/Response DTOs for all endpoints
- Integration with MediatR CQRS handlers

Total: 4 proto files, 4 service classes, 26 RPC endpoints
Build: ✅ Successful (0 errors)

src/CMSMicroservice.WebApi/Services/ConfigurationService.cs

@@ -0,0 +1,44 @@
+using CMSMicroservice.Protobuf.Protos.Configuration;
+using CMSMicroservice.WebApi.Common.Services;
+using CMSMicroservice.Application.ConfigurationCQ.Commands.SetConfigurationValue;
+using CMSMicroservice.Application.ConfigurationCQ.Commands.DeactivateConfiguration;
+using CMSMicroservice.Application.ConfigurationCQ.Queries.GetConfigurationByKey;
+using CMSMicroservice.Application.ConfigurationCQ.Queries.GetAllConfigurations;
+using CMSMicroservice.Application.ConfigurationCQ.Queries.GetConfigurationHistory;
+
+namespace CMSMicroservice.WebApi.Services;
+
+public class ConfigurationService : ConfigurationContract.ConfigurationContractBase
+{
+    private readonly IDispatchRequestToCQRS _dispatchRequestToCQRS;
+
+    public ConfigurationService(IDispatchRequestToCQRS dispatchRequestToCQRS)
+    {
+        _dispatchRequestToCQRS = dispatchRequestToCQRS;
+    }
+
+    public override async Task<Empty> CreateOrUpdateConfiguration(CreateOrUpdateConfigurationRequest request, ServerCallContext context)
+    {
+        return await _dispatchRequestToCQRS.Handle<CreateOrUpdateConfigurationRequest, SetConfigurationValueCommand>(request, context);
+    }
+
+    public override async Task<Empty> DeactivateConfiguration(DeactivateConfigurationRequest request, ServerCallContext context)
+    {
+        return await _dispatchRequestToCQRS.Handle<DeactivateConfigurationRequest, DeactivateConfigurationCommand>(request, context);
+    }
+
+    public override async Task<GetConfigurationByKeyResponse> GetConfigurationByKey(GetConfigurationByKeyRequest request, ServerCallContext context)
+    {
+        return await _dispatchRequestToCQRS.Handle<GetConfigurationByKeyRequest, GetConfigurationByKeyQuery, GetConfigurationByKeyResponse>(request, context);
+    }
+
+    public override async Task<GetAllConfigurationsResponse> GetAllConfigurations(GetAllConfigurationsRequest request, ServerCallContext context)
+    {
+        return await _dispatchRequestToCQRS.Handle<GetAllConfigurationsRequest, GetAllConfigurationsQuery, GetAllConfigurationsResponse>(request, context);
+    }
+
+    public override async Task<GetConfigurationHistoryResponse> GetConfigurationHistory(GetConfigurationHistoryRequest request, ServerCallContext context)
+    {
+        return await _dispatchRequestToCQRS.Handle<GetConfigurationHistoryRequest, GetConfigurationHistoryQuery, GetConfigurationHistoryResponse>(request, context);
+    }
+}