feat: Add GetClubStatistics and GetNetworkStatistics APIs with corresponding request and response messages

src/CMSMicroservice.Protobuf/Protos/clubmembership.proto

@@ -45,6 +45,11 @@ service ClubMembershipContract
             get: "/ClubMembership/GetHistory"
         };
     };
+    rpc GetClubStatistics(GetClubStatisticsRequest) returns (GetClubStatisticsResponse){
+        option (google.api.http) = {
+            get: "/ClubMembership/GetStatistics"
+        };
+    };
 }
 
 // Activate Command
@@ -164,3 +169,39 @@ message ClubMembershipHistoryModel
     string reason = 12;
     google.protobuf.Timestamp created = 13;
 }
+
+// GetClubStatistics Query
+message GetClubStatisticsRequest
+{
+    // Empty - returns overall club statistics
+}
+
+message GetClubStatisticsResponse
+{
+    int32 total_members = 1;
+    int32 active_members = 2;
+    int32 inactive_members = 3;
+    int32 expired_members = 4;
+    double active_percentage = 5;
+    repeated PackageLevelDistribution package_distribution = 6;
+    repeated MonthlyMembershipTrend monthly_trend = 7;
+    int64 total_revenue = 8;
+    double average_membership_duration_days = 9;
+    int32 expiring_soon_count = 10; // Expiring in next 30 days
+}
+
+message PackageLevelDistribution
+{
+    int64 package_id = 1;
+    string package_name = 2;
+    int32 member_count = 3;
+    double percentage = 4;
+}
+
+message MonthlyMembershipTrend
+{
+    string month = 1; // Format: "2025-11"
+    int32 activations = 2;
+    int32 expirations = 3;
+    int32 net_change = 4;
+}