feat(v1.1.9): queue:: Rhai SDK module

executor-core/sdk/queue.rs registers the queue:: namespace into the
per-call Rhai engine:

  queue::enqueue("name", message)               -> ()
  queue::enqueue("name", message, opts)         -> ()  // opts: Map
  queue::depth("name")                          -> i64
  queue::depth_pending("name")                  -> i64

No handle pattern (queues are the grouping unit, mirroring pubsub).
Opts map accepts optional delay_ms (i64) and max_attempts (u32);
unknown keys are silently ignored to match Rhai's Map semantics.

Bridge details:
- captures Arc<dyn QueueService> + Arc<SdkCallCx> per closure (cheap
  clone)
- block_on via TokioHandle::try_current() — same pattern pubsub/kv use
- message → JSON via a local message_to_json that base64-encodes Blobs
  at any depth (mirrors pubsub) and REJECTS FnPtr / closures with a
  clear error (queue messages must survive Postgres round-trip)
- depth / depth_pending clamp u64 → i64::MAX (Rhai's INT is i64)

register_all gains queue::register(...) positionally after pubsub.

Unit tests (executor-core --lib): blob → base64, nested-map round-trip,
FnPtr rejection, opts parsing (partial / max_attempts only / non-integer
delay rejection).

Integration tests (executor-core/tests/sdk_queue.rs, 6 binaries):
enqueue map payload, enqueue with opts threads through, blob base64
encodes, depth returns service value, FnPtr in payload throws, empty
queue_name throws.

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

crates/executor-core/src/sdk/mod.rs

@@ -20,6 +20,7 @@ pub mod files;
 pub mod http;
 pub mod kv;
 pub mod pubsub;
+pub mod queue;
 pub mod secrets;
 pub mod stdlib;
 pub mod users;
@@ -45,6 +46,7 @@ pub fn register_all(engine: &mut RhaiEngine, services: &Services, cx: Arc<SdkCal
     http::register(engine, services, cx.clone());
     files::register(engine, services, cx.clone());
     pubsub::register(engine, services, cx.clone());
+    queue::register(engine, services, cx.clone());
     secrets::register(engine, services, cx.clone());
     email::register(engine, services, cx.clone());
     users::register(engine, services, cx);