feat(build): scaffold working admin controllers with model, AdminFS and delete (quick-261028-pq8)

- make:admin-controller edits the singular of its name (--model overrides):
  ModelName, modelClass and the YAML under models/<model>/
- NewRecord returns &models.<Model>{} when the model exists; otherwise the
  nil body stays and the command says to run make:model
- config_list.yaml offers create and delete with showCheckboxes
- registry.gen.go embeds controllers/*/*.yaml and models/*/*.yaml once they
  exist and exposes generatedAdminFS(); scaffolded plugins implement
  pact.AdminAssets through it, and a plugin without AdminFS gets a note
- blog example moves its YAML to models/post; docs and help text follow

docs/examples/blog/plugin.go

@@ -38,9 +38,6 @@ var langFS embed.FS
 //go:embed views/mail
 var mailFS embed.FS
 
-//go:embed controllers/*/*.yaml models/*/*.yaml
-var adminFS embed.FS
-
 // Plugin is the acme.blog plugin, the Go form of Plugin.php.
 type Plugin struct {
 	app *backpack.App
@@ -79,9 +76,9 @@ func (p *Plugin) Commands() []bonfire.Command {
 	return append(generatedCommands(p.app), console.PublishCommand(p.withDB))
 }
 
-// AdminFS is the admin YAML the controllers read: controllers/posts and
-// models/posts.
-func (p *Plugin) AdminFS() fs.FS { return adminFS }
+// AdminFS is the admin YAML the controllers read, controllers/posts and
+// models/post, which registry.gen.go embeds.
+func (p *Plugin) AdminFS() fs.FS { return generatedAdminFS() }
 
 // Permissions replaces registerPermissions().
 func (p *Plugin) Permissions() []pact.Permission {