refactor(memory)!: remove the QMD backend; builtin is the only memory engine (#120936)

* refactor(memory): remove qmd backend

Make builtin the sole memory-core engine, rename the retained session helper barrel, retire QMD config with doctor migrations, and remove QMD runtime/UI/policy surfaces.

* docs(memory): remove qmd backend guidance

Delete the QMD concept page, rewrite memory documentation for builtin retrieval, and remove QMD from navigation and taxonomy source.

* refactor(memory): remove qmd-only leftovers

* refactor(memory): finish qmd integration cleanup

* build(deps): align root string-width types

* build(deps): model root string-width tooling

* refactor(memory): align qmd removal ui and docs

* fix(memory): preserve qmd external paths in doctor

* test(memory): remove obsolete backend probe case

* test(plugin-sdk): refresh private type baseline

src/plugins/contracts/extension-package-project-boundaries.test.ts

@@ -47,7 +47,7 @@ type PackageJson = {
 const MEMORY_HOST_SDK_EXPORTS = [
   "./engine-embeddings",
   "./engine-foundation",
-  "./engine-qmd",
+  "./engine-sessions",
   "./engine-storage",
   "./multimodal",
   "./query",
@@ -57,7 +57,6 @@ const MEMORY_HOST_SDK_EXPORTS = [
   "./status",
 ] as const;
 const MEMORY_HOST_SDK_ALLOWED_CORE_BRIDGE_FILES = [
-  "packages/memory-host-sdk/src/host/config-utils.ts",
   "packages/memory-host-sdk/src/host/openclaw-runtime-auth.ts",
   "packages/memory-host-sdk/src/host/openclaw-runtime-kysely.ts",
   "packages/memory-host-sdk/src/host/openclaw-runtime-network.ts",

src/plugins/loader.registration.test-utils.ts

@@ -754,7 +754,7 @@ describe("loadOpenClawPlugins", () => {
                   return { manager: null, error: "snapshot" };
                 },
                 resolveMemoryBackendConfig() {
-                  return { backend: "qmd", qmd: {} };
+                  return { backend: "builtin" };
                 },
               },
             });

src/plugins/provider-runtime.test.ts

@@ -874,7 +874,7 @@ describe("provider-runtime", () => {
       plugins: {
         entries: {
           demo: { enabled: true, config: { endpoint: "https://demo.example" } },
-          "active-memory": { enabled: true, config: { qmd: { searchMode: "fast" } } },
+          "active-memory": { enabled: true, config: { queryMode: "recent" } },
         },
       },
     } as OpenClawConfig;
@@ -1168,7 +1168,7 @@ describe("provider-runtime", () => {
       plugins: {
         entries: {
           demo: { enabled: true, config: { endpoint: "https://demo.example" } },
-          "active-memory": { enabled: true, config: { qmd: { searchMode: "fast" } } },
+          "active-memory": { enabled: true, config: { queryMode: "recent" } },
         },
       },
     } as OpenClawConfig;

src/plugins/registry-contribution-types.ts

@@ -254,13 +254,7 @@ export type MemoryFlushPlanResolver = (params: {
 
 export type RegisteredMemorySearchManager = MemorySearchManager;
 
-type MemoryRuntimeQmdConfig = {
-  command?: string;
-};
-
-type MemoryRuntimeBackendConfig =
-  | { backend: "builtin" }
-  | { backend: "qmd"; qmd?: MemoryRuntimeQmdConfig };
+type MemoryRuntimeBackendConfig = { backend: "builtin" };
 
 export type MemoryPluginRuntime = {
   getMemorySearchManager(params: {
@@ -270,19 +264,9 @@ export type MemoryPluginRuntime = {
   }): Promise<{
     manager: RegisteredMemorySearchManager | null;
     debug?: {
-      backend?: "builtin" | "qmd";
+      backend?: "builtin";
       purpose?: "default" | "status" | "cli";
       managerMs?: number;
-      managerCacheState?:
-        | "cached-full-hit"
-        | "cached-full-miss"
-        | "transient-cli"
-        | "transient-status"
-        | "pending-create-wait"
-        | "fallback-builtin"
-        | "recent-failure-cooldown";
-      qmdIdentityHash?: string;
-      failureCode?: "qmd-unavailable";
     };
     error?: string;
   }>;