feat: add terminal image foundation

- add terminal image service and image component

- protect image lines and clean up kitty image ids

test/TinyTUI.ComponentChecks/Program.cs

@@ -1,8 +1,12 @@
+using TinyTUI;
 using TinyTUI.Components;
 using TinyTUI.Autocomplete;
 using TinyTUI.Input;
 using TinyTUI.Rendering;
+using TinyTUI.Stdout;
+using TinyTUI.Terminal.Images;
 using TinyTUI.Text;
+using System.Text;
 
 var measurer = new TerminalTextMeasurer();
 
@@ -65,6 +69,49 @@ autocompleteEditor.HandleInput(new TuiInputEvent(TuiInputEventKind.Key, KeyNames
 AssertFalse(autocompleteEditor.IsAutocompleteActive, "autocomplete cancel");
 AssertEqual("/h", autocompleteEditor.Value, "autocomplete cancel keeps text");
 
+var imageService = new TerminalImageService();
+imageService.SetCapabilities(new TerminalCapabilities(ImageProtocol.Kitty, true, true));
+imageService.SetCellDimensions(new CellDimensions(10, 10));
+var cellSize = imageService.CalculateCellSize(new ImageDimensions(20, 20), 2);
+AssertEqual(new ImageCellSize(2, 2), cellSize, "image cell size");
+
+var pngData = Convert.FromBase64String("iVBORw0KGgoAAAANSUhEUgAAAAIAAAADCAIAAADZrBkAAAAACXBIWXMAAAsTAAALEwEAmpwYAAAAFElEQVR4nGNgYGBgYGBgYGBgAAAABQABJzQnCgAAAABJRU5ErkJggg==");
+AssertEqual(new ImageDimensions(2, 3), imageService.TryGetDimensions(pngData, "image/png"), "png dimensions");
+
+var image = new Image([1, 2, 3, 4], "image/png", imageService: imageService, dimensions: new ImageDimensions(20, 20))
+{
+    MaxWidthCells = 2,
+};
+var imageLines = image.Render(4);
+AssertEqual(2, imageLines.Count, "kitty image line count");
+AssertTrue(image.ImageId is > 0, "kitty image id allocated");
+AssertTrue(imageLines[0].StartsWith("\e_G", StringComparison.Ordinal), "kitty image sequence");
+AssertTrue(imageLines[0].Contains(",C=1,", StringComparison.Ordinal), "kitty image no cursor movement");
+AssertTrue(TerminalImageService.IsImageLine($"prefix {imageLines[0]} suffix"), "image line detection anywhere");
+
+imageService.SetCapabilities(TerminalCapabilities.Conservative);
+var fallback = new Image([1, 2, 3], "image/jpeg", imageService: imageService, dimensions: new ImageDimensions(8, 9))
+{
+    FileName = "photo.jpg",
+}.Render(80)[0];
+AssertTrue(fallback.Contains("[Image: photo.jpg [image/jpeg] 8x9]", StringComparison.Ordinal), "image fallback");
+
+var fakeOutput = new FakeTerminalOutput();
+var renderer = new DifferentialRenderer(
+    fakeOutput,
+    measurer,
+    new RenderPipelineOptions { ThrowOnWidthOverflow = true, UseSynchronizedOutput = false });
+var longImageLine = $"Read image file \e]1337;File=inline=1:{new string('A', 200)}\a";
+renderer.Render([longImageLine], new TerminalSize(20, 5));
+renderer.Render(["plain"], new TerminalSize(20, 5));
+
+fakeOutput.Buffer.Clear();
+var kittyLine = "\e_Ga=T,f=100,q=2,C=1,c=1,r=1,i=42;AAAA\e\\";
+renderer.Render([kittyLine], new TerminalSize(20, 5));
+fakeOutput.Buffer.Clear();
+renderer.Render(["changed"], new TerminalSize(20, 5));
+AssertTrue(fakeOutput.Buffer.ToString().Contains(TerminalImageService.DeleteKittyImage(42), StringComparison.Ordinal), "kitty image cleanup on diff");
+
 Console.WriteLine("TinyTUI component checks passed");
 
 static void AssertEqual<T>(T expected, T actual, string name)
@@ -80,3 +127,34 @@ static void AssertTrue(bool condition, string name)
 }
 
 static void AssertFalse(bool condition, string name) => AssertTrue(!condition, name);
+
+/// <summary>
+/// 捕获渲染器写出的终端序列
+/// </summary>
+internal sealed class FakeTerminalOutput : ITerminalOutput
+{
+    /// <summary>
+    /// 获取已写出的终端缓冲
+    /// </summary>
+    public StringBuilder Buffer { get; } = new();
+
+    /// <inheritdoc />
+    public void Write(string value) => Buffer.Append(value);
+
+    /// <inheritdoc />
+    public void Flush()
+    {
+    }
+
+    /// <inheritdoc />
+    public void ClearScreen() => Buffer.Append("\e[2J\e[H");
+
+    /// <inheritdoc />
+    public void HideCursor() => Buffer.Append("\e[?25l");
+
+    /// <inheritdoc />
+    public void ShowCursor() => Buffer.Append("\e[?25h");
+
+    /// <inheritdoc />
+    public void MoveCursorTo(int row, int column) => Buffer.Append($"\e[{row};{column}H");
+}