docs: Add comprehensive Dungeon Editor technical guide

- Introduced a new DUNGEON_EDITOR_COMPLETE_GUIDE.md that details the features, architecture, and usage of the Dungeon Editor.
- Documented critical bug fixes, including segfaults and loading order issues, along with their resolutions.
- Enhanced the guide with a structured overview, quick start instructions, and troubleshooting tips for users.
- Updated the architecture section to reflect the new card-based system and self-contained room management.
- Included detailed testing commands and expected outputs to assist developers in verifying functionality.

src/cli/handlers/agent/tool_commands.cc

@@ -551,7 +551,7 @@ absl::Status HandleDungeonDescribeRoomCommand(
         room.blockset, room.spriteset, room.palette);
     std::cout << absl::StrFormat(
         "  \"floors\": {\"primary\": %u, \"secondary\": %u},\n",
-        room.floor1, room.floor2);
+        room.floor1(), room.floor2());
     std::cout << absl::StrFormat(
         "  \"message_id\": \"0x%03X\",\n", room.message_id_);
     std::cout << absl::StrFormat(
@@ -625,7 +625,7 @@ absl::Status HandleDungeonDescribeRoomCommand(
         room.blockset, room.spriteset, room.palette);
     std::cout << absl::StrFormat(
         "  Floors → Main:%u Alt:%u  Message ID:0x%03X  Hole warp:0x%02X\n",
-        room.floor1, room.floor2, room.message_id_, room.holewarp);
+        room.floor1(), room.floor2(), room.message_id_, room.holewarp);
     if (!stairs.empty()) {
       std::cout << "  Staircases:\n";
       for (const auto& stair : stairs) {