feat(build): mark scaffolded files with //summer:make and pass the app to generated commands (quick-261028-pq8)

- model, migration, command, job and admin-controller stubs start with
  //summer:make <kind>; registry.gen.go keeps its generated-code header
- the registry scan accepts the directive and the older header
- command functions may take one *backpack.App; generatedCommands takes a
  variadic app, so plugin.go files calling generatedCommands() still compile
- scaffolded plugins keep the app from Boot and return generatedCommands(p.app)
- make:command notes the nil app for an older plugin.go
- docs, help text and the blog example follow

docs/console/scaffolding.md

@@ -126,12 +126,14 @@ summer make:model Comment
 |---------|--------|-------|
 | `summer make:model` | `models/<name>.go` and `updates/<timestamp>_create_<table>.go` | The table name is the plugin ID and the plural name in snake case, such as `acme_blog_posts`. `--no-migration` skips the migration. |
 | `summer make:migration` | `updates/<timestamp>_<name>.go` | An empty gormigrate migration with up and down steps to fill in. |
-| `summer make:command` | `console/<name>.go` | A `bonfire.Command` named `<plugin>:<name>`, such as `blog:publish`. |
+| `summer make:command` | `console/<name>.go` | A `bonfire.Command` named `<plugin>:<name>`, such as `blog:publish`, from a function that takes the `*backpack.App` the plugin kept from `Boot`. A scaffolded plugin's `Commands` returns `generatedCommands(p.app)`; when `plugin.go` still calls `generatedCommands()` without the app, the command notes that the function receives `nil`. |
 | `summer make:job` | `jobs/<name>.go` | A typed job built with `conga.Job`; the plugin never imports the queue library. |
 | `summer make:admin-controller` | `controllers/<name>.go`, `controllers/<name>/config_form.yaml`, `controllers/<name>/config_list.yaml`, `models/<name>/fields.yaml`, `models/<name>/columns.yaml` | A `pact.AdminController` with WinterCMS-shaped form and list configuration. It already requires the permission `<plugin>.access_<name>`, which you declare in the plugin's `Permissions()`, and its `NewRecord` returns `nil` until you return your model, so the screens stay closed until you finish it. |
 
 File names are the snake-case form of the name: `AddPublishedAt` becomes `add_published_at`. Migration file names start with a 14-digit UTC timestamp. Each new migration gets a timestamp after every file already in `updates/`: the current second, or one second past the newest existing migration when that is not earlier. File names therefore sort in creation order, and so does the list in `registry.gen.go`, even for migrations made within one second.
 
+Every file these commands write for you to edit starts with the line `//summer:make <kind>`, such as `//summer:make model` or `//summer:make admin-controller`. Keep it: `registry.gen.go` lists only the files that carry it, or the older `// Code generated by summer make. DO NOT EDIT.` header, which earlier versions wrote and which is still recognised. `registry.gen.go` itself keeps that header, so it is the only file linters treat as generated.
+
 After writing the files, every `make:` command regenerates the plugin's `registry.gen.go`, which lists the plugin's models, migrations, commands, jobs and admin controllers, and runs `go mod tidy` in the plugin. The capability methods of a scaffolded `plugin.go` return those generated lists. If your `plugin.go` was written by hand and does not call them, the command prints a note naming the accessors to add.
 
 Each command prints `Created <path>` for every file it writes. A command refuses to overwrite an existing file or to declare a name the package already has.