fix(core): preserve SDK plugins across location eviction (#35725)

packages/core/src/plugin/sdk.ts

@@ -7,14 +7,6 @@ import { EventV2 } from "../event"
 
 export const Updated = EventV2.ephemeral({ type: "sdk.plugin.updated", schema: {} })
 
-export interface Store {
-  readonly plugins: Map<string, Plugin>
-}
-
-export const makeStore = (): Store => ({ plugins: new Map() })
-
-const defaultStore = makeStore()
-
 /**
  * Holds the plugins an embedder (the `@opencode-ai/sdk-next` host) contributes,
  * so `PluginSupervisor` can add them on every Location boot through the ordinary
@@ -22,10 +14,9 @@ const defaultStore = makeStore()
  * config. Registration publishes an unlocated update so every booted Location
  * reloads its plugin generation from the shared store.
  *
- * The store is shared explicitly between the SDK construction graph and the
- * embedded route graph because `LocationServiceMap` builds Location layers lazily
- * in a nested graph. Each embedded SDK creates its own store, so instances do not
- * see each other's contributions.
+ * Each host-global layer owns one private store. Location graphs reuse that
+ * layer through Effect's memoization, so separate hosts remain isolated while
+ * every Location in one host sees the same registrations.
  */
 export interface Interface {
   readonly register: (plugin: Plugin) => Effect.Effect<void>
@@ -34,26 +25,19 @@ export interface Interface {
 
 export class Service extends Context.Service<Service, Interface>()("@opencode/SdkPlugins") {}
 
-export const layerWithStore = (store: Store) =>
-  Layer.effect(
-    Service,
-    Effect.gen(function* () {
-      const events = yield* EventV2.Service
-      yield* Effect.addFinalizer(() =>
+export const layer = Layer.effect(
+  Service,
+  Effect.gen(function* () {
+    const events = yield* EventV2.Service
+    const plugins = new Map<string, Plugin>()
+    return Service.of({
+      register: (plugin) =>
         Effect.sync(() => {
-          store.plugins.clear()
-        }),
-      )
-      return Service.of({
-        register: (plugin) =>
-          Effect.sync(() => {
-            store.plugins.set(plugin.id, plugin)
-          }).pipe(Effect.andThen(events.publish(Updated, {})), Effect.asVoid),
-        all: () => [...store.plugins.values()],
-      })
-    }),
-  )
-
-export const layer = layerWithStore(defaultStore)
+          plugins.set(plugin.id, plugin)
+        }).pipe(Effect.andThen(events.publish(Updated, {})), Effect.asVoid),
+      all: () => [...plugins.values()],
+    })
+  }),
+)
 
 export const node = makeGlobalNode({ service: Service, layer, deps: [EventV2.node] })