手册数值改为占位符，渲染时从 Tuning 取值；加规则文件和测试

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/Decentralized.Domain/TuningText.cs

@@ -0,0 +1,63 @@
+using System;
+using System.Globalization;
+using System.Reflection;
+using System.Text.RegularExpressions;
+
+namespace Decentralized.Domain
+{
+    /// <summary>
+    /// 文本里的数值占位符：<c>{Name}</c>、<c>{Name:%}</c>、<c>{Name[2]:%}</c>，也可以走嵌套类 <c>{Section.Name}</c>。
+    /// 手册等说明文字不直接写数字，渲染时从 <see cref="Tuning"/> 取值，数值一改文字跟着变。
+    /// <c>%</c> 把小数按百分比显示（0.03 → 3%）；不带格式时去掉多余的零。
+    /// </summary>
+    public static class TuningText
+    {
+        private static readonly Regex Placeholder = new Regex(@"\{([A-Za-z0-9_.]+)(?:\[(\d+)\])?(?::(%))?\}", RegexOptions.Compiled);
+
+        public static string Render(string text)
+        {
+            if (string.IsNullOrEmpty(text)) return text;
+            return Placeholder.Replace(text, m => TryValue(m.Groups[1].Value, m.Groups[2].Success ? int.Parse(m.Groups[2].Value) : -1, out var v)
+                ? Format(v, m.Groups[3].Success)
+                : m.Value);
+        }
+
+        /// <summary>文本里取不到值的占位符（测试用）。</summary>
+        public static System.Collections.Generic.List<string> Unresolved(string text)
+        {
+            var bad = new System.Collections.Generic.List<string>();
+            foreach (Match m in Placeholder.Matches(text ?? ""))
+                if (!TryValue(m.Groups[1].Value, m.Groups[2].Success ? int.Parse(m.Groups[2].Value) : -1, out _)) bad.Add(m.Value);
+            return bad;
+        }
+
+        private static string Format(double v, bool percent)
+        {
+            if (percent) v *= 100;
+            return Math.Round(v, 4).ToString("0.####", CultureInfo.InvariantCulture) + (percent ? "%" : "");
+        }
+
+        private static bool TryValue(string path, int index, out double value)
+        {
+            value = 0;
+            var type = typeof(Tuning);
+            var parts = path.Split('.');
+            for (int i = 0; i < parts.Length - 1; i++)
+            {
+                type = type.GetNestedType(parts[i], BindingFlags.Public | BindingFlags.Static);
+                if (type == null) return false;
+            }
+            var field = type.GetField(parts[parts.Length - 1], BindingFlags.Public | BindingFlags.Static);
+            if (field == null) return false;
+            var raw = field.GetValue(null);
+            if (raw is Array arr)
+            {
+                if (index < 0 || index >= arr.Length) return false;
+                raw = arr.GetValue(index);
+            }
+            else if (index >= 0) return false;
+            try { value = Convert.ToDouble(raw, CultureInfo.InvariantCulture); return true; }
+            catch (Exception) { return false; }
+        }
+    }
+}