Initial Agentsd project commit

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

core/agentsd/src/callback.rs

@@ -0,0 +1,47 @@
+use std::collections::HashMap;
+use std::sync::Mutex;
+use tokio::sync::mpsc;
+
+/// A fired timer event delivered to the plugin that created it.
+#[derive(Clone, Debug)]
+pub struct TimerEvent {
+    pub timer_id: String,
+    pub callback_id: String,
+}
+
+/// Manages per-plugin event channels for timer callbacks.
+pub struct CallbackBus {
+    senders: Mutex<HashMap<String, mpsc::Sender<TimerEvent>>>,
+}
+
+impl CallbackBus {
+    pub fn new() -> Self {
+        Self {
+            senders: Mutex::new(HashMap::new()),
+        }
+    }
+
+    /// Register a plugin and get a receiver for its timer events.
+    pub fn subscribe(&self, plugin_id: &str) -> mpsc::Receiver<TimerEvent> {
+        let (tx, rx) = mpsc::channel(64);
+        self.senders
+            .lock()
+            .unwrap()
+            .insert(plugin_id.to_string(), tx);
+        rx
+    }
+
+    /// Deliver a timer event to the target plugin.
+    pub fn fire(&self, plugin_id: &str, event: TimerEvent) {
+        let senders = self.senders.lock().unwrap();
+        if let Some(tx) = senders.get(plugin_id) {
+            // Non-blocking send; drop if channel full
+            let _ = tx.try_send(event);
+        }
+    }
+
+    /// Remove a plugin's channel (on unregister/disconnect).
+    pub fn remove(&self, plugin_id: &str) {
+        self.senders.lock().unwrap().remove(plugin_id);
+    }
+}