feat: implement ADR-007 subscription transport — PendingRequestMap.subscribe(), CallHandler dispatch, SSE AsyncGenerator handlers

Add remote subscription support so spokes can consume streaming operations
over pubsub transports (WebSocket, Redis). Extract checkAccess to access.ts
to break circular dep between call.ts and subscribe.ts.

docs/architecture/adapters.md

@@ -1,6 +1,6 @@
 ---
-status: draft
-last_updated: 2026-05-11
+status: stable
+last_updated: 2026-05-16
 ---
 
 # Adapters

docs/architecture/api-surface.md

@@ -1,6 +1,6 @@
 ---
-status: draft
-last_updated: 2026-05-11
+status: stable
+last_updated: 2026-05-16
 ---
 
 # API Surface

docs/architecture/call-protocol.md

@@ -1,6 +1,6 @@
 ---
-status: draft
-last_updated: 2026-05-11
+status: stable
+last_updated: 2026-05-16
 ---
 
 # Call Protocol

docs/architecture/decisions/007-subscription-transport.md

@@ -1,6 +1,6 @@
 ---
-status: draft
-last_updated: 2026-05-13
+status: accepted
+last_updated: 2026-05-16
 ---
 
 # ADR-007: Subscription Transport for SSE and Remote Streaming

docs/architecture/response-envelopes.md

@@ -1,6 +1,6 @@
 ---
-status: draft
-last_updated: 2026-05-11
+status: stable
+last_updated: 2026-05-16
 ---
 
 # Response Envelopes
@@ -514,9 +514,9 @@ The following **code** changes are pending:
 
 | Code | Change | Status |
 |------|--------|--------|
-| `src/from_openapi.ts` | Generate `SubscriptionHandler` (AsyncGenerator) for SUBSCRIPTION operations, parse SSE stream, yield per-event | ❌ Not started |
-| `src/call.ts` | Add `PendingRequestMap.subscribe()` method using Repeater from `@alkdev/pubsub` | ❌ Not started |
-| `src/call.ts` | Update `CallHandler` to dispatch on operation type | ❌ Not started |
+| `src/from_openapi.ts` | Generate `SubscriptionHandler` (AsyncGenerator) for SUBSCRIPTION operations, parse SSE stream, yield per-event | ✅ Implemented |
+| `src/call.ts` | Add `PendingRequestMap.subscribe()` method using Repeater from `@alkdev/pubsub` | ✅ Implemented |
+| `src/call.ts` | Update `CallHandler` to dispatch on operation type | ✅ Implemented |
 | `src/subscribe.ts` | Ensure `subscribe()` handles `httpEnvelope` detection for SSE yields | ✅ Already handles envelopes |
 
 ## References