refactor(10.2-01): nest framework packages under modules

- Move remaining beach packages and embedded admin assets\n- Rewrite framework, example, build, and gate paths

modules/backpack/app.go

@@ -0,0 +1,74 @@
+package backpack
+
+import (
+	"fmt"
+	"sync"
+
+	"git.golem15.com/golem15/summercms/modules/compass"
+	"git.golem15.com/golem15/summercms/modules/festival"
+)
+
+// App is the per-instance application container. It must not import party.
+type App struct {
+	Config   *compass.Config
+	Services *Registry
+	Events   *festival.Bus
+
+	mu      sync.RWMutex
+	plugins map[string]struct{}
+}
+
+// New returns an App that owns cfg.
+func New(cfg *compass.Config) *App {
+	return &App{
+		Config:   cfg,
+		Services: NewRegistry(),
+		Events:   festival.New(),
+		plugins:  make(map[string]struct{}),
+	}
+}
+
+// SetPlugins records the complete activated plugin set. HasPlugin uses this
+// list, including plugins that have not yet Booted.
+func (a *App) SetPlugins(ids []string) {
+	if a == nil {
+		return
+	}
+	next := make(map[string]struct{}, len(ids))
+	for _, id := range ids {
+		if id != "" {
+			next[id] = struct{}{}
+		}
+	}
+	a.mu.Lock()
+	a.plugins = next
+	a.mu.Unlock()
+}
+
+// HasPlugin reports whether id is in the complete registered set.
+func (a *App) HasPlugin(id string) bool {
+	if a == nil {
+		return false
+	}
+	a.mu.RLock()
+	defer a.mu.RUnlock()
+	_, ok := a.plugins[id]
+	return ok
+}
+
+// Publish stores an app-scoped service under T.
+func (a *App) Publish[T any](value T) error {
+	if a == nil || a.Services == nil {
+		return fmt.Errorf("backpack: app has no service registry")
+	}
+	return a.Services.Publish(value)
+}
+
+// Lookup returns the app-scoped service published under T.
+func (a *App) Lookup[T any]() (T, bool) {
+	var zero T
+	if a == nil || a.Services == nil {
+		return zero, false
+	}
+	return a.Services.Lookup[T]()
+}