Simplify to transport-only: remove call protocol, add EventEnvelope, expand stream operators

- Remove src/call.ts (PendingRequestMap, CallEventSchema, CallError) — call protocol belongs in @alkdev/operations
- Add EventEnvelope type ({ type, id, payload }) as the cross-platform serialization contract
- Simplify createPubSub: replace PubSubPublishArgsByKey tuple model with PubSubEventMap; publish(type, id, payload) and subscribe(type, id) use explicit id for topic scoping
- Update Redis adapter to serialize/deserialize full EventEnvelope
- Expand operators: add take, reduce, toArray, batch, dedupe, window, flat, groupBy, chain, join
- Remove @alkdev/typebox runtime dependency (was only used by call.ts)
- Remove ./call sub-path export from package.json and tsup config
- Update all architecture docs to reflect transport-only scope, add Worker adapter, remove call protocol references
- Remove docs/architecture/call-protocol.md
- Update AGENTS.md with new source layout and transport-only principle

docs/architecture/iroh-transport.md

@@ -1,6 +1,6 @@
 ---
 status: draft
-last_updated: 2026-04-30
+last_updated: 2026-05-01
 ---
 
 # Iroh Transport
@@ -36,7 +36,7 @@ Using `@rayhanadev/iroh` (v0.1.1) as the NAPI-RS binding. Community binding, one
 | `Connection.remoteNodeId()` | Get peer's public key |
 | `Connection.sendDatagram()` / `readDatagram()` | Unreliable datagrams |
 
-Not exposed (not critical): `Endpoint.watch_addr()`, `Connection.close_reason()`, `Connection.stats()`.
+Not exposed (not critical): `Endpoint.watchAddr()`, `Connection.close_reason()`, `Connection.stats()`.
 
 ## Protocol
 
@@ -54,13 +54,13 @@ QUIC streams are byte streams (no message boundaries). We use 4-byte big-endian
 
 ### Message Format
 
-Same `type` + `detail` shape as all other transports:
+All transports use the `EventEnvelope` format:
 
 ```json
-{ "type": "call.requested", "detail": { ... } }
+{ "type": "call.responded", "id": "uuid-123", "payload": { "output": 42 } }
 ```
 
-Maps directly to `new CustomEvent(type, { detail })`.
+On the wire, this serializes as the JSON payload after the length prefix. When received, it maps to `new CustomEvent("call.responded:uuid-123", { detail: envelope })`.
 
 ## Two-Sided Design