feat(migration): migrate legacy owner data and update config reference handling

- Implemented a migration process to move resources from the legacy owner "default" to the new default owner "local", ensuring no data loss during the transition.
- Updated configuration reference handling to replace legacy `$VAR_`, `$SECRET_`, and `$CONTEXT_` prefixes with mustache-style `{{ vars.name }}`, `{{ secrets.name }}`, and `{{ context.name }}`.
- Enhanced YAML configuration files and scripts to reflect the new mustache syntax, improving consistency across the application.
- Added tests to validate the migration process and ensure proper handling of legacy references.
- Updated documentation to guide users on the new configuration reference format.

packages/server/test/profiles-smoke.js

@@ -71,11 +71,11 @@ const created = await upsertProfile({
   owner,
   name,
   script: "ntfy.js",
-  config: { url: "$VAR_ntfy_channel" },
+  config: { url: "{{ vars.ntfy_channel }}" },
   description: "smoke",
 });
 assert(created.name === name, "created");
-assert(created.config.url === "$VAR_ntfy_channel", "config roundtrip");
+assert(created.config.url === "{{ vars.ntfy_channel }}", "config roundtrip");
 assert(created.script === "ntfy.js", "script locked on profile");
 
 const fetched = await getProfilePlain(owner, name);