feat: Artisan checklist for application commands, hints and coverage gate

- migrate, migrate:rollback and deferred:purge gain --pretend and --force;
  they and queue:clear confirm only in production on an interactive
  terminal, so deploys over SSH proceed as before
- result lines: Applied N migrations, Rolled back <id> of <plugin>,
  Cleared N jobs from <queue>
- --json for migrate:status, key:generate, route:list, admin:token:create,
  admin:token:list, admin:token:scopes and websockets:health; -q keeps the
  key and the token
- hints for an empty DSN, an unreachable database, an invalid app.key, a
  missing uploads bucket and an application binary run below its root
- flare and websockets:health return bonfire.Reported after printing
- long help and examples for every application command, greeter:hello and
  blog:publish; cmd/summer TestCommandsDocumented fails on any gap

examples/hello/plugins/greeter/plugin.go

@@ -79,6 +79,14 @@ func (p *Plugin) Commands() []bonfire.Command {
 	return []bonfire.Command{{
 		Name:        "greeter:hello",
 		Description: "Print the configured application name",
+		Long: `Prints app.name, golem15.hello.posts_per_page and app.debug from the layered
+configuration, then fires, collects and hands a HelloEvent to the event bus
+and reports what came back. The example application's tests use it to check
+configuration layering and events end to end.`,
+		Examples: []bonfire.Example{
+			{Command: "greeter:hello", Description: "Print the configured values"},
+			{Command: "greeter:hello --env production", Description: "Print the values of the production configuration"},
+		},
 		Run: func(ctx context.Context, in bonfire.Input, out bonfire.Output) error {
 			name := ""
 			posts := 0