Picture Debug: Replace "Chroma" with "Transparent" as this is the name the editor uses

Also Chroma is not really correct as this is about background removal and not about alpha transparency.

Cell index is now 1-based to match what the editor displays

Author: Ghabry

src/window_debug_picture.cpp

@@ -172,7 +172,7 @@ void Window_DebugPictureInfo::Refresh() {
 	// Common Flags
 	std::vector<FlagInfo> flags = {
 		{ "Fixed", d.fixed_to_map },
-		{ "Chroma", d.use_transparent_color },
+		{ "Transparent", d.use_transparent_color },
 		{ "Tint", d.flags.affected_by_tint },
 		{ "Flash", d.flags.affected_by_flash },
 		{ "Shake", d.flags.affected_by_shake },
@@ -192,7 +192,8 @@ void Window_DebugPictureInfo::Refresh() {
 		y = DrawLine(y, "File", name_str);
 
 		if (d.spritesheet_cols > 1 || d.spritesheet_rows > 1) {
-			std::string cell_str = fmt::format("#{} ({}x{})", d.spritesheet_frame, d.spritesheet_cols, d.spritesheet_rows);
+			// The editor frame number is 1-based so the user should see the expected value here
+			std::string cell_str = fmt::format("#{} ({}x{})", d.spritesheet_frame + 1, d.spritesheet_cols, d.spritesheet_rows);
 			y = DrawLine(y, "Cell", cell_str);
 
 			if (d.spritesheet_speed > 0) {