docs: surface Arcp\Ids and Arcp\Clock namespaces; fix sessions/jobs links and Transport::send signature

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: nficano

docs/README.md

@@ -42,12 +42,14 @@ across multiple npm packages. PHP ships as one Composer package,
 | --- | --- |
 | `Arcp\Envelope`, `Arcp\Json` | Wire envelope model and serialization |
 | `Arcp\Messages` | Typed protocol payloads |
+| `Arcp\Ids` | Typed IDs (`SessionId`, `JobId`, `TraceId`, etc.) |
 | `Arcp\Errors` | Canonical error codes and exceptions |
 | `Arcp\Client` | `ARCPClient` and client-side handlers |
 | `Arcp\Runtime` | `ARCPRuntime`, jobs, leases, artifacts, subscriptions |
 | `Arcp\Transport` | WebSocket, stdio, and in-memory transports |
 | `Arcp\Auth` | Built-in auth schemes and `AuthRouter` |
 | `Arcp\Store` | Event log and idempotency persistence |
+| `Arcp\Clock` | Time source abstraction for deterministic tests |
 | `Arcp\Extensions` | Vendor extension classification |
 | `Arcp\Cli` | `bin/arcp` commands |
 

docs/architecture.md

@@ -12,6 +12,7 @@ that map to the same layers as the TypeScript SDK packages.
 | Runtime | `Arcp\Runtime`, `Arcp\Internal\Runtime` |
 | Transports | `Arcp\Transport` |
 | Persistence | `Arcp\Store` |
+| Time | `Arcp\Clock` |
 | Extensions | `Arcp\Extensions` |
 
 The public surface is intentionally small: `ARCPClient`, `ARCPRuntime`,

docs/getting-started.md

@@ -78,8 +78,8 @@ child owns the runtime.
 
 ## What's next
 
-- [Sessions](./architecture.md)
-- [Jobs](./architecture.md)
+- [Sessions](./guides/sessions.md)
+- [Jobs](./guides/jobs.md)
 - [Transports](./transports.md)
 - [Recipes](./recipes.md)
 

docs/transports.md

@@ -5,7 +5,7 @@ The transport interface is `Arcp\Transport\Transport`:
 ```php
 interface Transport
 {
-    public function send(Envelope $env): void;
+    public function send(Envelope $env, ?Cancellation $cancellation = null): void;
     public function receive(?Cancellation $cancellation = null): ?Envelope;
     public function close(): void;
     public function isClosed(): bool;