feat(plugins): add joplin-api and send-sms under repo-root plugins/

Load user plugins from /plugins instead of data/plugins so site-specific scripts stay in git and workflows can reference plugin/joplin-api and plugin/send-sms.

Co-authored-by: Cursor <cursoragent@cursor.com>

.gitignore

@@ -7,6 +7,8 @@ logs/
 packages/web/dist
 
 # Personal/local scripts and workflows (not for the repo)
-packages/server/scripts/dev-*
-packages/server/workflows/**/dev-*
 debug-*.js
+
+# Plugin install staging and per-plugin deps
+plugins/.staging-*
+plugins/*/node_modules/