feat(http/gateway/invoke-streaming): add GatewayDispatch::invoke_streaming

Add the streaming analogue of invoke() returning BoxStream<ResponseEnvelope>.
Security invariants are identical to invoke() (internal: false,
forwarded_for: None, same capabilities/scoped_env/ACL) — shared via a
build_root_context_inner helper with a bounded flag. The streaming path
sets deadline: None (unbounded subscriptions, ADR-049 §6). Calls
OperationRegistry::invoke_streaming() (already on develop). to_mcp is
unchanged (MCP excludes Subscription, ADR-041).

Tests cover: subscription dispatch, leading-slash strip, unknown op
NOT_FOUND, internal op NOT_FOUND (not leaked), None identity FORBIDDEN,
Query op INVALID_OPERATION_TYPE, invoke() on Subscription returns
INVALID_OPERATION_TYPE (guard holds through gateway), and
build_root_context_streaming sets deadline: None while carrying the
registration bundle.

crates/alknet-http/src/gateway/dispatch.rs

@@ -26,6 +26,7 @@ use alknet_call::registry::env::LocalOperationEnv;
 use alknet_call::registry::registration::OperationRegistry;
 use alknet_core::auth::{AuthToken, Identity, IdentityProvider};
 use alknet_core::types::Capabilities;
+use futures::stream::BoxStream;
 use serde_json::Value;
 
 const DEFAULT_TIMEOUT: Duration = Duration::from_secs(30);
@@ -70,11 +71,43 @@ impl GatewayDispatch {
         self.registry.invoke(&operation_name, input, context).await
     }
 
+    pub fn invoke_streaming(
+        &self,
+        identity: Option<Identity>,
+        op: &str,
+        input: Value,
+    ) -> BoxStream<'static, ResponseEnvelope> {
+        let operation_name = strip_leading_slash(op).to_string();
+        let request_id = uuid::Uuid::new_v4().to_string();
+        let context = self.build_root_context_streaming(&request_id, &operation_name, identity);
+        self.registry
+            .invoke_streaming(&operation_name, input, context)
+    }
+
     fn build_root_context(
         &self,
         request_id: &str,
         operation_name: &str,
         identity: Option<Identity>,
+    ) -> OperationContext {
+        self.build_root_context_inner(request_id, operation_name, identity, true)
+    }
+
+    fn build_root_context_streaming(
+        &self,
+        request_id: &str,
+        operation_name: &str,
+        identity: Option<Identity>,
+    ) -> OperationContext {
+        self.build_root_context_inner(request_id, operation_name, identity, false)
+    }
+
+    fn build_root_context_inner(
+        &self,
+        request_id: &str,
+        operation_name: &str,
+        identity: Option<Identity>,
+        bounded: bool,
     ) -> OperationContext {
         let registration = self.registry.registration(operation_name);
         let (composition_authority, capabilities, scoped_env) = match registration {
@@ -97,7 +130,7 @@ impl GatewayDispatch {
             forwarded_for: None,
             capabilities,
             metadata: HashMap::new(),
-            deadline: Some(Instant::now() + DEFAULT_TIMEOUT),
+            deadline: bounded.then(|| Instant::now() + DEFAULT_TIMEOUT),
             scoped_env,
             env,
             abort_policy: AbortPolicy::default(),
@@ -117,10 +150,11 @@ mod tests {
         services_list_handler, services_list_spec, services_schema_handler, services_schema_spec,
     };
     use alknet_call::registry::registration::{
-        make_handler, HandlerKind, HandlerRegistration, OperationProvenance,
+        make_handler, make_streaming_handler, HandlerKind, HandlerRegistration, OperationProvenance,
     };
     use alknet_call::registry::spec::{AccessControl, OperationSpec, OperationType, Visibility};
     use alknet_core::auth::AuthToken;
+    use futures::stream::StreamExt;
     use std::sync::Mutex as StdMutex;
 
     struct StaticIdentityProvider {
@@ -235,6 +269,53 @@ mod tests {
         registry
     }
 
+    fn subscription_spec(name: &str, visibility: Visibility, acl: AccessControl) -> OperationSpec {
+        OperationSpec::new(
+            name,
+            OperationType::Subscription,
+            visibility,
+            serde_json::json!({}),
+            serde_json::json!({}),
+            vec![],
+            acl,
+        )
+    }
+
+    fn echo_streaming_handler() -> HandlerKind {
+        HandlerKind::Stream(make_streaming_handler(|input, context| {
+            futures::stream::iter(vec![ResponseEnvelope::ok(context.request_id, input)])
+        }))
+    }
+
+    fn registry_with_subscription(
+        name: &str,
+        visibility: Visibility,
+        acl: AccessControl,
+    ) -> OperationRegistry {
+        let mut registry = OperationRegistry::new();
+        registry
+            .register(HandlerRegistration::new(
+                subscription_spec(name, visibility, acl),
+                echo_streaming_handler(),
+                OperationProvenance::Local,
+                None,
+                None,
+                Capabilities::new(),
+            ))
+            .unwrap();
+        registry
+    }
+
+    async fn collect_stream(
+        mut stream: BoxStream<'static, ResponseEnvelope>,
+    ) -> Vec<ResponseEnvelope> {
+        let mut out = Vec::new();
+        while let Some(env) = stream.next().await {
+            out.push(env);
+        }
+        out
+    }
+
     fn dispatch(
         registry: Arc<OperationRegistry>,
         provider: Arc<dyn IdentityProvider>,
@@ -548,4 +629,195 @@ mod tests {
         fn assert_concrete<T: Sized>() {}
         assert_concrete::<GatewayDispatch>();
     }
+
+    #[tokio::test]
+    async fn invoke_streaming_on_subscription_returns_handler_stream() {
+        let registry = Arc::new(registry_with_subscription(
+            "events/stream",
+            Visibility::External,
+            AccessControl::default(),
+        ));
+        let provider: Arc<dyn IdentityProvider> = Arc::new(StaticIdentityProvider::new());
+        let dp = dispatch(registry, provider);
+
+        let stream = dp.invoke_streaming(None, "events/stream", serde_json::json!({ "v": 7 }));
+        let items = collect_stream(stream).await;
+        assert_eq!(items.len(), 1);
+        assert_eq!(items[0].result, Ok(serde_json::json!({ "v": 7 })));
+    }
+
+    #[tokio::test]
+    async fn invoke_streaming_strips_leading_slash_from_operation_name() {
+        let registry = Arc::new(registry_with_subscription(
+            "events/stream",
+            Visibility::External,
+            AccessControl::default(),
+        ));
+        let provider: Arc<dyn IdentityProvider> = Arc::new(StaticIdentityProvider::new());
+        let dp = dispatch(registry, provider);
+
+        let stream = dp.invoke_streaming(None, "/events/stream", serde_json::json!({}));
+        let items = collect_stream(stream).await;
+        assert_eq!(items.len(), 1);
+        assert!(items[0].result.is_ok());
+    }
+
+    #[tokio::test]
+    async fn invoke_streaming_on_unknown_op_yields_single_not_found() {
+        let registry = Arc::new(OperationRegistry::new());
+        let provider: Arc<dyn IdentityProvider> = Arc::new(StaticIdentityProvider::new());
+        let dp = dispatch(registry, provider);
+
+        let stream = dp.invoke_streaming(None, "no/such", serde_json::json!({}));
+        let items = collect_stream(stream).await;
+        assert_eq!(items.len(), 1);
+        match &items[0].result {
+            Err(e) => {
+                assert_eq!(e.code, "NOT_FOUND");
+                assert!(e.message.contains("no/such"));
+            }
+            other => panic!("expected NOT_FOUND, got {other:?}"),
+        }
+    }
+
+    #[tokio::test]
+    async fn invoke_streaming_on_internal_op_from_external_yields_not_found() {
+        let registry = Arc::new(registry_with_subscription(
+            "secret/stream",
+            Visibility::Internal,
+            AccessControl::default(),
+        ));
+        let provider: Arc<dyn IdentityProvider> = Arc::new(StaticIdentityProvider::new());
+        let dp = dispatch(registry, provider);
+
+        let stream = dp.invoke_streaming(None, "secret/stream", serde_json::json!({}));
+        let items = collect_stream(stream).await;
+        assert_eq!(items.len(), 1);
+        match &items[0].result {
+            Err(e) => {
+                assert_eq!(e.code, "NOT_FOUND");
+                assert!(e.message.contains("secret/stream"));
+            }
+            other => panic!("expected NOT_FOUND, got {other:?}"),
+        }
+    }
+
+    #[tokio::test]
+    async fn invoke_streaming_with_none_identity_and_restricted_op_yields_forbidden() {
+        let registry = Arc::new(registry_with_subscription(
+            "admin/stream",
+            Visibility::External,
+            AccessControl {
+                required_scopes: vec!["admin".to_string()],
+                ..Default::default()
+            },
+        ));
+        let provider: Arc<dyn IdentityProvider> = Arc::new(StaticIdentityProvider::new());
+        let dp = dispatch(registry, provider);
+
+        let stream = dp.invoke_streaming(None, "admin/stream", serde_json::json!({}));
+        let items = collect_stream(stream).await;
+        assert_eq!(items.len(), 1);
+        match &items[0].result {
+            Err(e) => {
+                assert_eq!(e.code, "FORBIDDEN");
+                assert_eq!(e.message, "authentication required");
+            }
+            other => panic!("expected FORBIDDEN, got {other:?}"),
+        }
+    }
+
+    #[tokio::test]
+    async fn invoke_streaming_on_query_op_yields_invalid_operation_type() {
+        let registry = Arc::new(registry_with(
+            "echo/run",
+            Visibility::External,
+            AccessControl::default(),
+        ));
+        let provider: Arc<dyn IdentityProvider> = Arc::new(StaticIdentityProvider::new());
+        let dp = dispatch(registry, provider);
+
+        let stream = dp.invoke_streaming(None, "echo/run", serde_json::json!({}));
+        let items = collect_stream(stream).await;
+        assert_eq!(items.len(), 1);
+        match &items[0].result {
+            Err(e) => assert_eq!(e.code, "INVALID_OPERATION_TYPE"),
+            other => panic!("expected INVALID_OPERATION_TYPE, got {other:?}"),
+        }
+    }
+
+    #[tokio::test]
+    async fn invoke_on_subscription_op_returns_invalid_operation_type() {
+        let registry = Arc::new(registry_with_subscription(
+            "events/stream",
+            Visibility::External,
+            AccessControl::default(),
+        ));
+        let provider: Arc<dyn IdentityProvider> = Arc::new(StaticIdentityProvider::new());
+        let dp = dispatch(registry, provider);
+
+        let response = dp
+            .invoke(None, "events/stream", serde_json::json!({}))
+            .await;
+        match response.result {
+            Err(e) => assert_eq!(e.code, "INVALID_OPERATION_TYPE"),
+            other => panic!("expected INVALID_OPERATION_TYPE, got {other:?}"),
+        }
+    }
+
+    #[test]
+    fn build_root_context_streaming_sets_deadline_none() {
+        let registry = Arc::new(registry_with_subscription(
+            "events/stream",
+            Visibility::External,
+            AccessControl::default(),
+        ));
+        let provider: Arc<dyn IdentityProvider> = Arc::new(StaticIdentityProvider::new());
+        let dp = dispatch(registry, provider);
+
+        let ctx = dp.build_root_context_streaming("req-st-1", "events/stream", None);
+        assert!(!ctx.internal, "internal must be false for wire-ingress");
+        assert!(ctx.forwarded_for.is_none(), "forwarded_for must be None");
+        assert!(ctx.parent_request_id.is_none(), "root has no parent");
+        assert!(
+            ctx.deadline.is_none(),
+            "deadline must be None for streaming"
+        );
+    }
+
+    #[test]
+    fn build_root_context_streaming_carries_registration_bundle_fields() {
+        let authority = alknet_call::registry::context::CompositionAuthority::new(
+            "agent",
+            ["fs:read".to_string()],
+        );
+        let scoped = ScopedPeerEnv::new(["fs/readFile"]);
+        let caps = Capabilities::new().with_api_key("google", "k".to_string());
+
+        let mut registry = OperationRegistry::new();
+        registry
+            .register(HandlerRegistration::new(
+                subscription_spec(
+                    "agent/stream",
+                    Visibility::External,
+                    AccessControl::default(),
+                ),
+                echo_streaming_handler(),
+                OperationProvenance::Local,
+                Some(authority),
+                Some(scoped.clone()),
+                caps,
+            ))
+            .unwrap();
+        let registry = Arc::new(registry);
+        let provider: Arc<dyn IdentityProvider> = Arc::new(StaticIdentityProvider::new());
+        let dp = dispatch(registry, provider);
+
+        let ctx = dp.build_root_context_streaming("req-st-2", "agent/stream", None);
+        assert!(ctx.handler_identity.is_some());
+        assert_eq!(ctx.handler_identity.as_ref().unwrap().label, "agent");
+        assert!(ctx.scoped_env.allows("fs/readFile"));
+        assert!(ctx.capabilities.get("google").is_some());
+        assert!(ctx.deadline.is_none());
+    }
 }