feat(plugins): core read-only scripts and user plugin system

Introduce plugin/<id> installs (zip, HTTPS git, example, fork),
jerapah-plugin.json manifests with jerapah semver ranges, isolated
plugin dirs under data/plugins, and app version 0.1.0. Core scripts
are non-editable; get-current-time moves to examples/plugins.

Co-authored-by: Nasyarobby Putra <nasyarobby@gmail.com>

packages/web/src/lib/workflow-doc.js

@@ -5,7 +5,7 @@ const HTTP_METHODS = ["GET", "HEAD", "POST", "PUT", "PATCH", "DELETE", "OPTIONS"
 
 export const NEW_WORKFLOW_YAML = `name: new workflow
 scripts:
-  - get-current-time.js
+  - plugin/get-current-time
 triggers:
   - type: HTTP
     method: POST