feat: Add unit tests and fakes for Crestron environment and data store

- Introduced `FakeCrestronEnvironment` and `FakeEthernetHelper` for testing purposes.
- Implemented `InMemoryCrestronDataStore` to facilitate unit tests for data storage.
- Created `DebugServiceTests` to validate the behavior of debug-related services.
- Added project files for unit tests targeting .NET 9.0 with necessary dependencies.
- Developed production adapters (`CrestronConsoleAdapter`, `CrestronDataStoreAdapter`, `CrestronEnvironmentAdapter`, `CrestronEthernetAdapter`) to interface with the Crestron SDK.
- Updated `Debug` class to utilize injected service abstractions instead of direct SDK calls.
- Enhanced `ControlSystem` initialization to register service adapters before usage.

src/PepperDash.Core/Adapters/CrestronConsoleAdapter.cs

@@ -0,0 +1,35 @@
+using System;
+using Crestron.SimplSharp;
+using PdCore = PepperDash.Core.Abstractions;
+
+namespace PepperDash.Core.Adapters;
+
+/// <summary>
+/// Production adapter — delegates ICrestronConsole calls to the real Crestron SDK.
+/// </summary>
+public sealed class CrestronConsoleAdapter : PdCore.ICrestronConsole
+{
+    public void PrintLine(string message) => CrestronConsole.PrintLine(message);
+
+    public void Print(string message) => CrestronConsole.Print(message);
+
+    public void ConsoleCommandResponse(string message) =>
+        CrestronConsole.ConsoleCommandResponse(message);
+
+    public void AddNewConsoleCommand(
+        Action<string> callback,
+        string command,
+        string helpText,
+        PdCore.ConsoleAccessLevel accessLevel)
+    {
+        var crestronLevel = accessLevel switch
+        {
+            PdCore.ConsoleAccessLevel.AccessAdministrator => ConsoleAccessLevelEnum.AccessAdministrator,
+            PdCore.ConsoleAccessLevel.AccessProgrammer => ConsoleAccessLevelEnum.AccessProgrammer,
+            _ => ConsoleAccessLevelEnum.AccessOperator,
+        };
+
+        // Wrap Action<string> in a lambda — Crestron's delegate is not a standard Action<string>.
+        CrestronConsole.AddNewConsoleCommand(s => callback(s), command, helpText, crestronLevel);
+    }
+}