feat: add getOutboundGateway effect and simplify VersionGraph init/uninit

Add getOutboundGateway effect across core, container-runtime, and SDK
to let services query their effective outbound gateway with callback
support. Remove preInstall/uninstall hooks from VersionGraph as they
are no longer needed.

sdk/base/lib/util/index.ts

@@ -14,6 +14,7 @@ export { once } from './once'
 export { asError } from './asError'
 export * as Patterns from './patterns'
 export * from './typeHelpers'
+export { GetOutboundGateway } from './GetOutboundGateway'
 export { GetSystemSmtp } from './GetSystemSmtp'
 export { Graph, Vertex } from './graph'
 export { inMs } from './inMs'