feat: implement workflow findings sharing for inter-agent communication in workflows

src/tool/spawn.rs

@@ -88,7 +88,7 @@ impl Tool for SpawnAgents {
             },
         };
 
-        use std::sync::Arc;
+        use std::sync::{Arc, Mutex};
         let live: Option<crate::app::workflow::engine::LiveStateFn> = _ctx.turn_events.as_ref().map(|turn_events| {
             let turn_events = turn_events.clone();
             let f: crate::app::workflow::engine::LiveStateFn = Arc::new(move |agent_id: String, status| {
@@ -104,6 +104,10 @@ impl Tool for SpawnAgents {
             f
         });
 
+        // Create a per-invocation findings scope so subagents spawned
+        // by this tool call are isolated from any other concurrent
+        // spawn_agents or workflow_run invocations.
+        let findings: Arc<Mutex<Vec<String>>> = Arc::new(Mutex::new(Vec::new()));
         let results = crate::app::workflow::engine::execute_primitive(
             &wf.script,
             &HashMap::new(),
@@ -112,6 +116,7 @@ impl Tool for SpawnAgents {
             live.as_ref(),
             &_ctx.session_dir,
             &_ctx.workspaces,
+            &findings,
         )?;
         format_results(results, "parallel")
     }
@@ -173,7 +178,7 @@ impl Tool for SpawnPipeline {
             },
         };
 
-        use std::sync::Arc;
+        use std::sync::{Arc, Mutex};
         let live: Option<crate::app::workflow::engine::LiveStateFn> = _ctx.turn_events.as_ref().map(|turn_events| {
             let turn_events = turn_events.clone();
             let f: crate::app::workflow::engine::LiveStateFn = Arc::new(move |agent_id: String, status| {
@@ -189,6 +194,9 @@ impl Tool for SpawnPipeline {
             f
         });
 
+        // Per-invocation findings scope isolates this pipeline from any
+        // other concurrent spawn_agents / spawn_pipeline / workflow_run.
+        let findings: Arc<Mutex<Vec<String>>> = Arc::new(Mutex::new(Vec::new()));
         let results = crate::app::workflow::engine::execute_primitive(
             &wf.script,
             &HashMap::new(),
@@ -197,6 +205,7 @@ impl Tool for SpawnPipeline {
             live.as_ref(),
             &_ctx.session_dir,
             &_ctx.workspaces,
+            &findings,
         )?;
         format_results(results, "pipeline")
     }