Add live debugger frontend and mutex stall recovery (#383)

src/SharpEmu.Debugger/Session/DebugStopReason.cs

@@ -0,0 +1,32 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+namespace SharpEmu.Debugger.Session;
+
+/// <summary>Why the target stopped and handed control to the debugger.</summary>
+public enum DebugStopReason
+{
+    /// <summary>Stopped at the configured entry point before running any frame.</summary>
+    EntryPoint,
+
+    /// <summary>An execution breakpoint was hit.</summary>
+    Breakpoint,
+
+    /// <summary>A data watchpoint was hit.</summary>
+    Watchpoint,
+
+    /// <summary>A single-step (frame step) request completed.</summary>
+    Step,
+
+    /// <summary>A client-requested pause took effect.</summary>
+    Pause,
+
+    /// <summary>The guest raised a fault or trap.</summary>
+    Fault,
+
+    /// <summary>
+    /// The backend detected an execution stall (for example a mutex spin loop /
+    /// livelock) with no forward progress.
+    /// </summary>
+    Stall,
+}