Add project files (part 1/2)

Co-Authored-By: Claude Sonnet 5 <[email protected]>

injector/tui.hpp

@@ -0,0 +1,40 @@
+// The loader's terminal UI: the four-frame Slinky logo and the sliding
+// underscore line, ported from the Go loader (animation/animation.go) so the
+// injector looks and moves exactly like it.
+#pragma once
+
+#include <chrono>
+#include <string>
+
+namespace Tui {
+
+bool EnableAnsi();          // Windows: turn on VT processing; Linux: no-op
+bool StdoutIsTty();
+
+std::string Logo(int frame);
+std::string ErrorLogo();
+std::string SlinkyLine(int frame);
+
+class Screen {
+public:
+    explicit Screen(bool animate);
+    ~Screen();
+
+    Screen(const Screen&) = delete;
+    Screen& operator=(const Screen&) = delete;
+
+    void Render(const std::string& title, const std::string& message, bool error = false);
+private:
+    // The animation advances with time, not with redraws: the caller redraws every ~16 ms so status
+    // messages show up at once, which made a frame-per-redraw animation run at 60 fps.
+    static constexpr int kFrameMs = 100;
+    int Frame() const;
+
+    bool animate_;
+    std::chrono::steady_clock::time_point start_ = std::chrono::steady_clock::now();
+    // Last rendered content: the caller redraws at 60 Hz, but the frame only changes every
+    // kFrameMs (or on a status change), so identical redraws are skipped.
+    std::string last_body_;
+};
+
+}  // namespace Tui