chore: import upstream snapshot with attribution

example/c-vt-encode-mouse/src/main.c

@@ -0,0 +1,52 @@
+#include <assert.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+#include <ghostty/vt.h>
+
+//! [mouse-encode]
+int main() {
+  // Create encoder
+  GhosttyMouseEncoder encoder;
+  GhosttyResult result = ghostty_mouse_encoder_new(NULL, &encoder);
+  assert(result == GHOSTTY_SUCCESS);
+
+  // Configure SGR format with normal tracking
+  ghostty_mouse_encoder_setopt(encoder, GHOSTTY_MOUSE_ENCODER_OPT_EVENT,
+      &(GhosttyMouseTrackingMode){GHOSTTY_MOUSE_TRACKING_NORMAL});
+  ghostty_mouse_encoder_setopt(encoder, GHOSTTY_MOUSE_ENCODER_OPT_FORMAT,
+      &(GhosttyMouseFormat){GHOSTTY_MOUSE_FORMAT_SGR});
+
+  // Set terminal geometry for coordinate mapping
+  ghostty_mouse_encoder_setopt(encoder, GHOSTTY_MOUSE_ENCODER_OPT_SIZE,
+      &(GhosttyMouseEncoderSize){
+          .size = sizeof(GhosttyMouseEncoderSize),
+          .screen_width = 800, .screen_height = 600,
+          .cell_width = 10, .cell_height = 20,
+      });
+
+  // Create and configure a left button press event
+  GhosttyMouseEvent event;
+  result = ghostty_mouse_event_new(NULL, &event);
+  assert(result == GHOSTTY_SUCCESS);
+  ghostty_mouse_event_set_action(event, GHOSTTY_MOUSE_ACTION_PRESS);
+  ghostty_mouse_event_set_button(event, GHOSTTY_MOUSE_BUTTON_LEFT);
+  ghostty_mouse_event_set_position(event,
+      (GhosttyMousePosition){.x = 50.0f, .y = 40.0f});
+
+  // Encode the mouse event
+  char buf[128];
+  size_t written = 0;
+  result = ghostty_mouse_encoder_encode(encoder, event,
+      buf, sizeof(buf), &written);
+  assert(result == GHOSTTY_SUCCESS);
+
+  // Use the encoded sequence (e.g., write to terminal)
+  fwrite(buf, 1, written, stdout);
+
+  // Cleanup
+  ghostty_mouse_event_free(event);
+  ghostty_mouse_encoder_free(encoder);
+  return 0;
+}
+//! [mouse-encode]