refactor: move bundled plugin policy into manifests

src/plugin-sdk/memory-core-engine-runtime.ts

@@ -2,6 +2,9 @@
 // Keep extension-owned engine exports isolated behind a dedicated SDK subpath.
 
 export {
+  getBuiltinMemoryEmbeddingProviderDoctorMetadata,
   getMemorySearchManager,
+  listBuiltinAutoSelectMemoryEmbeddingProviderDoctorMetadata,
   MemoryIndexManager,
 } from "../../extensions/memory-core/runtime-api.js";
+export type { BuiltinMemoryEmbeddingProviderDoctorMetadata } from "../../extensions/memory-core/runtime-api.js";

src/plugin-sdk/provider-env-vars.ts

@@ -1,6 +1,7 @@
 // Public provider auth environment variable helpers for plugin runtimes.
 
 export {
+  getProviderEnvVars,
   listKnownProviderAuthEnvVarNames,
   omitEnvKeysCaseInsensitive,
 } from "../secrets/provider-env-vars.js";