test: validate localization key parity and format placeholders

Add LocalizationValidationTests to catch regressions in translation PRs:

- AllLocales_HaveExactlySameKeysAsEnUs: asserts every locale under
  Strings/ has exactly the same resource key set as en-us — no missing
  or extra entries. Runs against all present locales (zh-cn, and any
  future ones like fr-fr from PR #69).

- AllLocales_PreserveFormatPlaceholders: asserts that {0}/{1}/...
  format placeholders in translated values match the en-us source,
  preventing runtime FormatException from mistranslated strings.

95 Tray tests pass (93 existing + 2 new).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: github-actions[bot]

tests/OpenClaw.Tray.Tests/LocalizationValidationTests.cs

@@ -0,0 +1,117 @@
+using System.Text.RegularExpressions;
+using System.Xml.Linq;
+
+namespace OpenClaw.Tray.Tests;
+
+/// <summary>
+/// Validates that all localization resource files are consistent with en-us.
+/// Catches missing/extra keys and broken format placeholders early — before translation PRs land.
+/// </summary>
+public class LocalizationValidationTests
+{
+    private static string GetRepositoryRoot()
+    {
+        var envRepoRoot = Environment.GetEnvironmentVariable("OPENCLAW_REPO_ROOT");
+        if (!string.IsNullOrWhiteSpace(envRepoRoot) && Directory.Exists(envRepoRoot))
+            return envRepoRoot;
+
+        var directory = new DirectoryInfo(AppContext.BaseDirectory);
+        while (directory != null)
+        {
+            if (Directory.Exists(Path.Combine(directory.FullName, ".git")) &&
+                File.Exists(Path.Combine(directory.FullName, "README.md")))
+                return directory.FullName;
+            directory = directory.Parent;
+        }
+
+        throw new InvalidOperationException(
+            "Could not find repository root. Set OPENCLAW_REPO_ROOT to the repo path.");
+    }
+
+    private static string GetStringsDirectory() =>
+        Path.Combine(GetRepositoryRoot(), "src", "OpenClaw.Tray.WinUI", "Strings");
+
+    private static Dictionary<string, string> LoadResw(string path)
+    {
+        var doc = XDocument.Load(path);
+        return doc.Descendants("data")
+            .ToDictionary(
+                e => e.Attribute("name")!.Value,
+                e => e.Element("value")?.Value ?? string.Empty);
+    }
+
+    [Fact]
+    public void AllLocales_HaveExactlySameKeysAsEnUs()
+    {
+        var stringsDir = GetStringsDirectory();
+        var referencePath = Path.Combine(stringsDir, "en-us", "Resources.resw");
+        Assert.True(File.Exists(referencePath), $"Reference file not found: {referencePath}");
+
+        var referenceKeys = LoadResw(referencePath).Keys.ToHashSet(StringComparer.Ordinal);
+
+        var localeDirs = Directory.GetDirectories(stringsDir)
+            .Where(d => !string.Equals(Path.GetFileName(d), "en-us", StringComparison.OrdinalIgnoreCase))
+            .ToList();
+
+        Assert.NotEmpty(localeDirs);
+
+        foreach (var localeDir in localeDirs)
+        {
+            var locale = Path.GetFileName(localeDir);
+            var reswPath = Path.Combine(localeDir, "Resources.resw");
+            Assert.True(File.Exists(reswPath), $"Expected Resources.resw for locale '{locale}'.");
+
+            var localeKeys = LoadResw(reswPath).Keys.ToHashSet(StringComparer.Ordinal);
+
+            var missing = referenceKeys.Except(localeKeys).OrderBy(k => k).ToList();
+            var extra = localeKeys.Except(referenceKeys).OrderBy(k => k).ToList();
+
+            Assert.True(missing.Count == 0,
+                $"Locale '{locale}' is missing {missing.Count} key(s): {string.Join(", ", missing.Take(10))}");
+            Assert.True(extra.Count == 0,
+                $"Locale '{locale}' has {extra.Count} unexpected key(s): {string.Join(", ", extra.Take(10))}");
+        }
+    }
+
+    [Fact]
+    public void AllLocales_PreserveFormatPlaceholders()
+    {
+        var stringsDir = GetStringsDirectory();
+        var referenceResw = LoadResw(Path.Combine(stringsDir, "en-us", "Resources.resw"));
+
+        var keysWithPlaceholders = referenceResw
+            .Where(kv => Regex.IsMatch(kv.Value, @"\{\d+\}"))
+            .ToList();
+
+        if (keysWithPlaceholders.Count == 0)
+            return;
+
+        var localeDirs = Directory.GetDirectories(stringsDir)
+            .Where(d => !string.Equals(Path.GetFileName(d), "en-us", StringComparison.OrdinalIgnoreCase));
+
+        foreach (var localeDir in localeDirs)
+        {
+            var locale = Path.GetFileName(localeDir);
+            var reswPath = Path.Combine(localeDir, "Resources.resw");
+            if (!File.Exists(reswPath)) continue;
+
+            var localeResw = LoadResw(reswPath);
+
+            foreach (var (key, enValue) in keysWithPlaceholders)
+            {
+                if (!localeResw.TryGetValue(key, out var localeValue))
+                    continue;
+
+                var enPlaceholders = Regex.Matches(enValue, @"\{\d+\}")
+                    .Select(m => m.Value).OrderBy(p => p).ToList();
+                var localePlaceholders = Regex.Matches(localeValue, @"\{\d+\}")
+                    .Select(m => m.Value).OrderBy(p => p).ToList();
+
+                Assert.True(enPlaceholders.SequenceEqual(localePlaceholders),
+                    $"Locale '{locale}', key '{key}': expected placeholders " +
+                    $"[{string.Join(", ", enPlaceholders)}] but found " +
+                    $"[{string.Join(", ", localePlaceholders)}]");
+            }
+        }
+    }
+}