refactor(core): align architecture with cordis spatiotemporal composability

backend/core/context.go

@@ -10,6 +10,7 @@ import (
 	"sync"
 	"time"
 
+	"Wavelet/core/contracts"
 	"Wavelet/core/extpoints"
 )
 
@@ -214,6 +215,24 @@ func (c *Context) Setting() extpoints.SettingExtension {
 	return c.settings
 }
 
+// DB returns the contracts.DBService registered in the IoC container, or nil if not registered.
+func (c *Context) DB() contracts.DBService {
+	svc, err := Inject[contracts.DBService](c)
+	if err != nil {
+		return nil
+	}
+	return svc
+}
+
+// Cache returns the contracts.CacheService registered in the IoC container, or nil if not registered.
+func (c *Context) Cache() contracts.CacheService {
+	svc, err := Inject[contracts.CacheService](c)
+	if err != nil {
+		return nil
+	}
+	return svc
+}
+
 // OnDispose registers a cleanup callback function to be executed when this Context is disposed.
 // It accepts func() error, func(), or Disposer.
 func (c *Context) OnDispose(fn any) {