Package subscribers and recipes in sample/

What a package's own subscribers hear and emit, and how jadpo package check compiles a package's recipes in its sample/ app.

• What a package's subscriber hears. A subscriber in a package's subscribers/ listens with on: for an event its webhooks bring: one of the package's events with wire_name:, its provider declaring webhooks:, public or not. Any other event, the package's own events among them, is subscriber.event_invalid, so what a package makes of a webhook is for the app's subscribers. Its run: calls one of the package's own actions with the event or its fields (subscriber.run_invalid otherwise); retry: is as any subscriber's.
• Through the connection it came in on. A package's subscriber hears each connection that gives its package webhooks: { secret: }, and only the events that came in on that connection: one delivery each, named subscriber <Package>.<name> <connection> (subscriber AcmePay.renewal payments), so a package connected twice runs its subscriber once per webhook, through the connection the webhook named. Its action's operations go through that connection, with its credential, host, timeout and fake; its changing calls are the delivery's steps, keyed by the delivery, as a subscriber's action's are; and a delivery is held while that connection's circuit breaker is open.
• What a package's action emits. An action without public, which only the package's subscribers run, emits the package's own events. An event a package's action emits and that gives no wire_name: is the package's own, and needs neither wire_name: nor occurred_at; wire_name: marks an event the provider sends, and emitting one is package.action_invalid, since only a signed webhook brings it. An event with neither wire_name: nor an action emitting it is still package.wire_name_invalid in a package that receives webhooks. What it emits is kept where the package's webhooks are, events: { store: } or the only store of the app's records, and reaches the app's subscribers of its public events; a package's subscriber never hears it, and one without public reaches no one.
• Recipes in sample/. jadpo package check compiles each recipe on its own, copied into the one domain of the package's sample/ app (its app.jadpo and domains/), with the package placed as the sample's own integration, as the bar places it for its own compile, so a recipe names the package as an app's own integration does; the migrations and records a recipe would need aren't asked for, since an app writes its own once it copies the recipe. The recipes row reads 1 recipe compiles in sample/, or which didn't; a recipe's problem is shown at recipes/<recipe>/<file> and a problem of the sample's own at sample/<file>, once. A package with recipes and no sample/app.jadpo, or a sample with no domain or several, is publish.sample_missing. The row isn't shown for a package with no recipes, and waits when the package has errors. A recipe's own tests run in sample/ once a recipe has some.