Integrate AI Agent Services and Chat Interface

- Added support for AI agent services, including `ConversationalAgentService`, to facilitate user interactions through a chat interface.
- Implemented `ChatTUI` for a terminal-based chat experience, allowing users to send messages and receive responses from the AI agent.
- Updated `EditorManager` to include options for displaying the agent chat widget and performance dashboard.
- Enhanced CMake configurations to include new source files for AI services and chat interface components.

This commit significantly expands the functionality of the z3ed system, paving the way for a more interactive and user-friendly experience in ROM hacking.

src/cli/handlers/agent.cc

@@ -65,6 +65,9 @@ absl::Status Agent::Run(const std::vector<std::string>& arg_vec) {
   if (subcommand == "dungeon-list-sprites") {
     return agent::HandleDungeonListSpritesCommand(subcommand_args);
   }
+  if (subcommand == "chat") {
+    return agent::HandleChatCommand();
+  }
 
   return absl::InvalidArgumentError(std::string(agent::kUsage));
 }