feat(01-01): boot hello app and dispatch greeter:hello

- Add party plugin registry with Register-before-Boot activation
- Add backpack, compass, bonfire, and pact capability interfaces
- Add examples/hello with two compiled plugin modules

pact/capabilities.go

@@ -0,0 +1,34 @@
+package pact
+
+import (
+	"io/fs"
+
+	"git.golem15.com/golem15/summercms/bonfire"
+)
+
+// HasCommands is implemented by plugins that register console commands.
+type HasCommands interface {
+	Commands() []bonfire.Command
+}
+
+// HasConfig is implemented by plugins that ship default YAML configuration.
+// ConfigFS should contain files such as config/config.yaml, merged later at
+// the plugin ID path.
+type HasConfig interface {
+	ConfigFS() fs.FS
+}
+
+// Reserved KERN-03 capability names, declared when their first consumers exist:
+//
+//	HasModels
+//	HasMigrations
+//	HasRoutes
+//	HasMiddleware
+//	HasJobs
+//	HasListeners
+//	HasAdminControllers
+//	HasNavigation
+//	HasPermissions
+//	HasSchedule
+//	HasMailTemplates
+//	HasLang