feat(mosstank): add VTank-style automation PoC

tests/AcDream.App.Tests/Plugins/FilePluginStorageTests.cs

@@ -0,0 +1,35 @@
+using AcDream.App.Plugins;
+
+namespace AcDream.App.Tests.Plugins;
+
+public sealed class FilePluginStorageTests
+{
+    [Fact]
+    public void WriteReadReplaceAndDeleteStayUnderConfiguredRoot()
+    {
+        string root = Path.Combine(
+            Path.GetTempPath(),
+            $"acdream-plugin-storage-{Guid.NewGuid():N}");
+        try
+        {
+            var storage = new FilePluginStorage(root);
+            storage.WriteText("plugin/profile.json", "one");
+            storage.WriteText("plugin/imports/route.nav", "nav");
+            Assert.Equal("one", storage.ReadText("plugin/profile.json"));
+            storage.WriteText("plugin/profile.json", "two");
+            Assert.Equal("two", storage.ReadText("plugin/profile.json"));
+            Assert.Equal(
+                ["plugin/imports/route.nav"],
+                storage.List("plugin/imports"));
+            Assert.True(storage.Delete("plugin/profile.json"));
+            Assert.Null(storage.ReadText("plugin/profile.json"));
+            Assert.Throws<ArgumentException>(() =>
+                storage.WriteText("../escape.json", "bad"));
+        }
+        finally
+        {
+            if (Directory.Exists(root))
+                Directory.Delete(root, recursive: true);
+        }
+    }
+}