Add AgentBBS connector plugin

Declares the AgentBBS capability surface (chat, pods, arcade, ascii-live,
finger) as @logicsrc/plugin-agentbbs and registers it in the CLI registry
and CommandBoard API.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

plugins/agentbbs/tsconfig.json

@@ -0,0 +1,8 @@
+{
+  "extends": "../../tsconfig.base.json",
+  "compilerOptions": {
+    "rootDir": "src",
+    "outDir": "dist"
+  },
+  "include": ["src/**/*.ts"]
+}