Add FanControl.ChromeboxEC plugin, project background, ectool docs

- Add FanControl.ChromeboxEC plugin for Fan Control
- Add project background/缘由 in README (EN/zh)
- Add docs/ectool-commands-zh.md
- Update sln, appsettings, gitignore

Made-with: Cursor

FanControl.ChromeboxEC/ChromeboxECFanSensor.cs

@@ -0,0 +1,27 @@
+using FanControl.Plugins;
+
+namespace FanControl.ChromeboxEC;
+
+/// <summary>风扇转速：ectool pwmgetfanrpm [index|all]</summary>
+public sealed class ChromeboxECFanSensor : IPluginSensor
+{
+    private readonly string _ectoolPath;
+    private readonly string[] _rpmArgs;
+
+    public ChromeboxECFanSensor(string ectoolPath, string[] rpmArgs)
+    {
+        _ectoolPath = ectoolPath;
+        _rpmArgs = rpmArgs is { Length: > 0 } ? rpmArgs : ["pwmgetfanrpm", "0"];
+    }
+
+    public string Id => "ChromeboxEC_Fan";
+    public string Name => "Chromebox EC Fan RPM";
+    public string Origin => "ectool pwmgetfanrpm";
+    public float? Value { get; private set; }
+
+    public void Update()
+    {
+        var (ok, stdout, _) = EctoolRunner.Run(_ectoolPath, _rpmArgs);
+        Value = ok && EctoolRunner.TryParseFanRpm(stdout) is { } rpm ? rpm : null;
+    }
+}