Initial commit: JDE Scoping Tool migration project

Set up repository with legacy .NET Framework 4.8 source (OLD/),
new .NET 10 Blazor solution (NEW/), OpenSpec specifications,
documentation, and project configuration.

OLD/DataModel/Db/DbManager.cs

@@ -0,0 +1,71 @@
+using System;
+using System.Collections.Generic;
+using System.Data.Common;
+using System.Data.SqlClient;
+using DDTek.Oracle;
+using NLog;
+
+namespace DataModel.Db
+{
+    public class DbManager
+    {
+        private static readonly Logger logger = LogManager.GetCurrentClassLogger();
+
+        private static readonly Dictionary<string, DbConnectionString> connectionStrings = new Dictionary<string, DbConnectionString>();
+
+
+        public static void Initialize(List<DbConnectionString> dbConnectionStrings)
+        {
+            foreach (DbConnectionString dbConnectionString in dbConnectionStrings)
+            {
+                connectionStrings.Add(dbConnectionString.Name, dbConnectionString);
+            }
+        }
+
+        public static DbConnection GetConnection(string name)
+        {
+            if (!connectionStrings.TryGetValue(name, out var connectionString))
+            {
+                throw new Exception($"DB Connection definition for '{name}' not found.");
+            }
+
+            DbConnection connection = connectionString.GetConnection();
+
+            try
+            {
+                connection.Open();
+            }
+            catch (Exception error)
+            {
+                string errorMessage = $"Failed to open DB connection to '{name}': {error.Message}.";
+                logger.Error(errorMessage);
+                throw new Exception(errorMessage, error);
+            }
+
+            return connection;
+        }
+    }
+
+    public enum DbTypes { SqlServer, Oracle }
+
+    public class DbConnectionString
+    {
+        public string Environment { get; set; }
+        public DbTypes DbType { get; set; }
+        public string Name { get; set; }
+        public string ConnectionString { get; set; }
+
+        public DbConnection GetConnection()
+        {
+            switch (DbType)
+            {
+                case DbTypes.Oracle:
+                    return new OracleConnection(ConnectionString);
+                case DbTypes.SqlServer:
+                    return new SqlConnection(ConnectionString);
+                default:
+                    return null;
+            }
+        }
+    }
+}