fix(runtime): protect active ACP tasks from idle cleanup

crates/aionui-ai-agent/src/active_lease.rs

@@ -0,0 +1,105 @@
+use aionui_common::{TimestampMs, now_ms};
+use dashmap::DashMap;
+
+pub const ACTIVE_LEASE_TTL_MS: TimestampMs = 90_000;
+
+#[derive(Debug)]
+pub struct ActiveLeaseRegistry {
+    leases: DashMap<String, TimestampMs>,
+    ttl_ms: TimestampMs,
+}
+
+impl ActiveLeaseRegistry {
+    pub fn new() -> Self {
+        Self::with_ttl_ms(ACTIVE_LEASE_TTL_MS)
+    }
+
+    pub fn with_ttl_ms(ttl_ms: TimestampMs) -> Self {
+        Self {
+            leases: DashMap::new(),
+            ttl_ms,
+        }
+    }
+
+    pub fn renew(&self, conversation_id: &str) -> TimestampMs {
+        let expires_at = now_ms().saturating_add(self.ttl_ms);
+        self.leases.insert(conversation_id.to_owned(), expires_at);
+        expires_at
+    }
+
+    pub fn renew_many<'a>(&self, conversation_ids: impl IntoIterator<Item = &'a str>) -> (usize, TimestampMs) {
+        let expires_at = now_ms().saturating_add(self.ttl_ms);
+        let mut count = 0;
+        for conversation_id in conversation_ids {
+            self.leases.insert(conversation_id.to_owned(), expires_at);
+            count += 1;
+        }
+        (count, expires_at)
+    }
+
+    pub fn active_until(&self, conversation_id: &str) -> Option<TimestampMs> {
+        let expires_at = *self.leases.get(conversation_id)?;
+        if expires_at > now_ms() {
+            Some(expires_at)
+        } else {
+            self.leases.remove(conversation_id);
+            None
+        }
+    }
+
+    pub fn is_active(&self, conversation_id: &str) -> bool {
+        self.active_until(conversation_id).is_some()
+    }
+}
+
+impl Default for ActiveLeaseRegistry {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::time::Duration;
+
+    #[test]
+    fn renew_sets_active_lease() {
+        let registry = ActiveLeaseRegistry::new();
+
+        let expires_at = registry.renew("conv-1");
+
+        assert_eq!(registry.active_until("conv-1"), Some(expires_at));
+        assert!(registry.is_active("conv-1"));
+    }
+
+    #[test]
+    fn renew_many_sets_all_leases_and_returns_count() {
+        let registry = ActiveLeaseRegistry::new();
+
+        let (count, expires_at) = registry.renew_many(["conv-1", "conv-2"]);
+
+        assert_eq!(count, 2);
+        assert_eq!(registry.active_until("conv-1"), Some(expires_at));
+        assert_eq!(registry.active_until("conv-2"), Some(expires_at));
+    }
+
+    #[test]
+    fn active_lookup_returns_none_for_missing_lease() {
+        let registry = ActiveLeaseRegistry::new();
+
+        assert_eq!(registry.active_until("missing"), None);
+        assert!(!registry.is_active("missing"));
+    }
+
+    #[test]
+    fn active_lookup_lazily_removes_expired_lease() {
+        let registry = ActiveLeaseRegistry::with_ttl_ms(1);
+        registry.renew("conv-1");
+
+        std::thread::sleep(Duration::from_millis(5));
+
+        assert_eq!(registry.active_until("conv-1"), None);
+        assert!(!registry.leases.contains_key("conv-1"));
+    }
+}

crates/aionui-ai-agent/src/agent_task.rs

@@ -235,7 +235,10 @@ impl AgentInstance {
             Self::Acp(m) => m.kill_and_wait(reason),
             Self::Aionrs(m) => m.kill_and_wait(reason),
             #[cfg(any(test, feature = "test-support"))]
-            Self::Mock(_) => Box::pin(std::future::ready(())),
+            Self::Mock(m) => {
+                let _ = m.kill(reason);
+                Box::pin(std::future::ready(()))
+            }
         }
     }
 

crates/aionui-ai-agent/src/factory/acp.rs

@@ -151,7 +151,7 @@ pub(super) async fn build(
         arc.set_session_id(sid).await;
     }
 
-    // Open the ACP session eagerly so `POST /warmup` returns only after
+    // Open the ACP session eagerly so runtime preparation returns only after
     // session/new (or claude-meta-resume / session/load) and the first
     // reconcile pass have completed. Matches aionrs factory behaviour:
     // the caller sees "warmed up" == "ready for PUT /mode | /model".

crates/aionui-ai-agent/src/idle_scanner.rs

@@ -15,7 +15,7 @@ const SCAN_INTERVAL_SECS: u64 = 60;
 /// Start the background idle agent scanner.
 ///
 /// Periodically scans active tasks and kills ACP agents that have been
-/// idle (finished + no activity) beyond the configured threshold.
+/// idle (finished or warmup-only + no activity) beyond the configured threshold.
 ///
 /// The scanner runs until the provided `shutdown` signal resolves.
 pub fn start_idle_scanner(
@@ -59,7 +59,7 @@ fn scan_and_cleanup(manager: &Arc<dyn IWorkerTaskManager>, threshold_ms: i64) {
     let idle_ids = manager.collect_idle(threshold_ms);
 
     if idle_ids.is_empty() {
-        debug!(active = manager.active_count(), "Idle scan: no idle agents found");
+        debug!(active_count = manager.active_count(), "Idle scan: no idle agents found");
         return;
     }
 

crates/aionui-ai-agent/src/lib.rs

@@ -1,6 +1,7 @@
 #![warn(clippy::disallowed_types)]
 
 //! AI agent lifecycle, worker task dispatch, and skill management.
+pub mod active_lease;
 pub(crate) mod agent_runtime;
 pub mod agent_task;
 pub mod capability;
@@ -21,6 +22,7 @@ pub mod shared_kernel;
 pub mod task_manager;
 pub mod types;
 
+pub use active_lease::{ACTIVE_LEASE_TTL_MS, ActiveLeaseRegistry};
 pub use agent_runtime::AgentRuntime;
 #[cfg(any(test, feature = "test-support"))]
 pub use agent_task::IMockAgent;

crates/aionui-ai-agent/src/manager/acp/agent.rs

@@ -970,7 +970,7 @@ impl AcpAgentManager {
     }
 
     /// Pre-open the ACP session without sending a prompt. Called by the
-    /// factory after `AcpAgentManager::build` so `POST /warmup` returns
+    /// factory after `AcpAgentManager::build` so runtime preparation returns
     /// only after the session is ready to accept `set_mode` / `set_model`
     /// / `prompt`. Idempotent — if already opened, returns immediately.
     #[tracing::instrument(skip_all, fields(conversation_id = %self.params.conversation_id))]