feat(events): add generic Event Bus and /events/wait endpoint for agent wakeups

server/src/api/events.rs

@@ -0,0 +1,44 @@
+use crate::AppState;
+use axum::extract::{Query, State};
+use axum::response::IntoResponse;
+use std::collections::HashMap;
+use std::sync::Arc;
+use crate::state::GenericEvent;
+
+pub async fn wait_for_event_handler(
+    State(state): State<Arc<AppState>>,
+    Query(params): Query<HashMap<String, String>>,
+) -> impl IntoResponse {
+    let topic = params.get("topic").cloned();
+    let session_id = params.get("session_id").cloned();
+
+    let mut rx = state.handler.state.event_bus_tx.subscribe();
+
+    loop {
+        match rx.recv().await {
+            Ok(event) => {
+                let topic_matches = topic.as_ref().map_or(true, |t| t == &event.topic);
+                let session_matches = session_id.as_ref().map_or(true, |s| Some(s) == event.session_id.as_ref());
+
+                if topic_matches && session_matches {
+                    return axum::Json(event);
+                }
+            }
+            Err(_) => {
+                return axum::Json(GenericEvent {
+                    topic: "error".to_string(),
+                    session_id: None,
+                    payload: serde_json::json!({"error": "Event bus lagged or closed"}),
+                });
+            }
+        }
+    }
+}
+
+pub async fn post_event_handler(
+    State(state): State<Arc<AppState>>,
+    axum::Json(event): axum::Json<GenericEvent>,
+) -> impl IntoResponse {
+    let _ = state.handler.state.event_bus_tx.send(event);
+    axum::Json(serde_json::json!({"status": "ok"}))
+}