feat(cnb-board): add cnb-dev-env routes and related functionalities

- Implemented routes for cnb-board to fetch live environment configurations, repository info, build info, pull request info, NPC info, and comment info.
- Created a utility function to execute shell commands.
- Added a check to determine if the environment is a CNB environment.
- Introduced a method to retrieve live markdown content with detailed service access information.
- Enhanced system information retrieval with CPU, memory, and disk usage metrics.
- Established a module structure for better organization of cnb-board related functionalities.

agent/routes/cnb-board/modules/index.ts

@@ -0,0 +1 @@
+export * from './is-cnb.ts';

agent/routes/cnb-board/modules/is-cnb.ts

@@ -0,0 +1,6 @@
+import { useKey } from "@kevisual/context";
+
+export const isCnb = () => {
+  const CNB = useKey('CNB');
+  return !!CNB;
+}