feat: add ncurses-based TUI frontend with 8x8 clip grid and keyboard controls

Co-authored-by: aider (deepseek/deepseek-coder) <aider@aider.chat>

Let's craft the blocks.tui.h

@@ -0,0 +1,15 @@
+#ifndef TUI_H
+#define TUI_H
+
+#include "engine.h"
+
+// Initialize TUI
+void tui_init(Engine *engine);
+
+// Run the TUI main loop
+void tui_run(Engine *engine);
+
+// Cleanup TUI
+void tui_cleanup(void);
+
+#endif // TUI_H