feat(core): admit v2 skill guidance (#30843)

packages/core/src/system-context/registry.ts

@@ -0,0 +1,46 @@
+export * as SystemContextRegistry from "./registry"
+
+import { Context, Effect, Layer, Ref, Scope } from "effect"
+import { SystemContext } from "./index"
+
+export interface Contribution {
+  readonly key: SystemContext.Key
+  readonly load: Effect.Effect<SystemContext.SystemContext>
+}
+
+export interface Interface {
+  readonly contribute: (contribution: Contribution) => Effect.Effect<void, never, Scope.Scope>
+  readonly load: () => Effect.Effect<SystemContext.SystemContext>
+}
+
+export class Service extends Context.Service<Service, Interface>()("@opencode/v2/SystemContextRegistry") {}
+
+export const layer = Layer.effect(
+  Service,
+  Effect.gen(function* () {
+    const contributions = yield* Ref.make<ReadonlyArray<Contribution>>([])
+
+    return Service.of({
+      contribute: Effect.fn("SystemContextRegistry.contribute")(function* (contribution) {
+        yield* Effect.acquireRelease(
+          Ref.modify(contributions, (current) => {
+            if (current.some((item) => item.key === contribution.key)) return [false, current]
+            return [true, [...current, contribution]]
+          }).pipe(
+            Effect.flatMap((added) =>
+              added ? Effect.void : Effect.die(`Duplicate system context contribution key: ${contribution.key}`),
+            ),
+            Effect.as(contribution),
+          ),
+          (entry) => Ref.update(contributions, (current) => current.filter((item) => item !== entry)),
+        )
+      }),
+      load: Effect.fn("SystemContextRegistry.load")(function* () {
+        const current = (yield* Ref.get(contributions)).toSorted((a, b) => (a.key < b.key ? -1 : a.key > b.key ? 1 : 0))
+        return SystemContext.combine(
+          yield* Effect.forEach(current, (contribution) => contribution.load, { concurrency: "unbounded" }),
+        )
+      }),
+    })
+  }),
+)