refactor: Implement dynamic skill loading from definitions, replacing hardcoded skills, and add a new skill management command.

Core/Skills/DynamicSkill.cs

@@ -0,0 +1,53 @@
+using System;
+using System.Diagnostics;
+
+namespace Toak.Core.Skills;
+
+public class DynamicSkill : ISkill
+{
+    private readonly SkillDefinition _def;
+
+    public string Name => _def.Name;
+    public string Description => _def.Description;
+    public string[] Hotwords => _def.Hotwords;
+    
+    public bool HandlesExecution => _def.Action.ToLowerInvariant() == "script";
+
+    public DynamicSkill(SkillDefinition def)
+    {
+        _def = def;
+    }
+
+    public string GetSystemPrompt(string rawTranscript)
+    {
+        return _def.SystemPrompt.Replace("{transcript}", rawTranscript);
+    }
+
+    public void Execute(string llmResult)
+    {
+        if (HandlesExecution && !string.IsNullOrWhiteSpace(_def.ScriptPath))
+        {
+            var expandedPath = Environment.ExpandEnvironmentVariables(_def.ScriptPath);
+            if (expandedPath.StartsWith("~"))
+            {
+                expandedPath = Environment.GetFolderPath(Environment.SpecialFolder.UserProfile) + expandedPath.Substring(1);
+            }
+
+            try
+            {
+                var process = Process.Start(new ProcessStartInfo
+                {
+                    FileName = expandedPath,
+                    Arguments = $"\"{llmResult.Replace("\"", "\\\"")}\"",
+                    UseShellExecute = false,
+                    CreateNoWindow = true
+                });
+                process?.WaitForExit();
+            }
+            catch (Exception ex)
+            {
+                Console.WriteLine($"[DynamicSkill] Error executing script '{expandedPath}': {ex.Message}");
+            }
+        }
+    }
+}