dbus: wire OnExit hook for detached process context injection

When a detached process exits, formats its output and calls
InjectSystemEvent on the agent core. Also emits ProcessExited
D-Bus signal for GUI notification.

main.go

@@ -179,6 +179,35 @@ func (m *SessionManager) CreateSession(cwd, backendName, modelName, agentName st
 	})
 	rt := agent.BuildRuntime(cfg, newDisp(), cwd, []string{"OLLIE_SESSION_ID=" + sessID})
 
+	// Wire OnExit hook so detached process exits get injected into agent context.
+	// We use a pointer indirection because core hasn't been created yet.
+	var coreRef agent.Core
+	if srv, ok := rt.Dispatcher.GetServer("execute"); ok {
+		type exitHooker interface {
+			SetOnExit(func(int, int))
+		}
+		if eh, ok := srv.(exitHooker); ok {
+			eh.SetOnExit(func(pid, exitCode int) {
+				if coreRef == nil {
+					return
+				}
+				var output string
+				type outputGetter interface {
+					GetDetachedOutput(int) (string, error)
+				}
+				if og, ok := srv.(outputGetter); ok {
+					output, _ = og.GetDetachedOutput(pid)
+				}
+				if len(output) > 2048 {
+					output = "[...truncated...]\n" + output[len(output)-2048:]
+				}
+				msg := fmt.Sprintf("pid %d exited with code %d\n%s", pid, exitCode, output)
+				coreRef.InjectSystemEvent(msg)
+				m.conn.Emit(busPath, busIface+".ProcessExited", sessID, int32(pid), int32(exitCode))
+			})
+		}
+	}
+
 	// Create the agent core
 	core := agent.NewAgentCore(agent.AgentCoreConfig{
 		Backend:       be,
@@ -190,6 +219,7 @@ func (m *SessionManager) CreateSession(cwd, backendName, modelName, agentName st
 		Runtime:       rt,
 		NewDispatcher: newDisp,
 	})
+	coreRef = core
 
 	ctx, cancel := context.WithCancel(context.Background())
 	sess := &managedSession{