docs(scope): record shared scoped-layer decision

packages/core/scope/README.md

@@ -12,6 +12,10 @@ Scoped registration primitive. `createScope(ctx, key)` creates a tagged Cordis c
 - `scopeTarget(base: T, key: ScopeKey | undefined): Scoped<T>` Build the opaque dispatch `thisArg` for a scope-filtered event. It composes `base`'s existing `Context.filter` with the scope predicate (untagged listener ⇒ admitted; tagged ⇒ admitted iff tag === key; `key === undefined` ⇒ untagged only). The carrier contains routing state only; the real subject is carried by the event arguments. `{ global: true }` listeners bypass filtering (Cordis semantics).
 - `Scoped<T>` The compile-time opaque carrier brand: scope-filtered events demand it as their `this` type, so dispatching with a bare subject is a compile error. The type parameter records the subject type but does not expose its properties.
 - `isScopeCarrier(value)` / `carrierKeyOf(value)` Runtime carrier marks, used by the dev invariants to assert every scope-filtered dispatch carries a carrier keyed to the subject its arguments name.
+- `ScopeLayer` Aggregate contract for one registry's complete global or exact-scope contribution; `isEmpty()` controls scoped-layer reclamation.
+- `ScopedLayers<L>` Own one eager global layer and lazy exact-scope layers. `peek()` never creates, `merge()` materializes insertion-ordered named shadows, and `effect()` derives visibility and ownership from the same context while returning the exact Cordis disposer.
+- `NamedEntries<V>` Insertion-ordered named storage with caller-owned duplicate diagnostics, live lookup/iteration, and an idempotent exact-entry undo from `insert()`.
+- `AnonymousEntries<V>` Insertion-ordered anonymous storage whose unique internal keys keep equal values as independent registrations; `append()` returns an idempotent exact-entry undo.
 
 The optional `@deepseek-ai/dsh-scope/invariant` companion owns that runtime assertion. It uses the generated `scoped-events.generated.ts` resolver map to require a carrier for every declared scoped event and, when the payload exposes its routing subject, require identity with the carrier key. The Program-backed generator derives the map from event declarations and real `scopeTarget(base, key)` calls.
 
@@ -19,6 +23,8 @@ The optional `@deepseek-ai/dsh-scope/invariant` companion owns that runtime asse
 
 The registration context determines both visibility and ownership, preventing a registration from being visible in one scope but disposed with another. Scopes route trusted same-process plugins; they are not sandboxes or authority boundaries. See the [agent-scope Agent Note](../../../.agents/notes/implemented/architecture/2026-07-08-agent-scope-contexts.md#security-and-authority-are-explicit-non-goals) for rationale and security non-goals.
 
+Scope-aware services define a concrete `ScopeLayer` that aggregates their heterogeneous tables and domain helpers. `ScopedLayers.effect()` accepts one synchronous action returning one synchronous undo, installs that undo before optional notification, and reclaims an exact-scope layer only when the complete aggregate is empty. `notify` defaults to `true`; the supplied callback owns whether observer failures throw or are contained. `EntryValues` remains internal, the storage classes are imported from the package root rather than a `/store` subpath, and the shared storage does not define registry-specific filtering or iteration policy. See the [shared scoped-layer storage Agent Note](../../../.agents/notes/implemented/architecture/2026-07-12-scoped-layers-store.md).
+
 Handing out a scoped context hands out the minting plugin's service-resolution surface (resolution walks the minting fiber's dependency chain, not the holder's) — mint it from the plugin whose dependencies the scoped registrations need to resolve.
 
 ## Known Limitations and Deferred Work