Add comprehensive plugin ecosystem documentation and examples

Co-authored-by: hotlong <50353452+hotlong@users.noreply.github.com>

Author: Copilot

content/docs/developers/meta.json

@@ -4,6 +4,7 @@
   "pages": [
     "micro-kernel",
     "writing-plugins",
+    "plugin-ecosystem",
     "custom-widgets",
     "server-drivers",
     "cli-tools"