fix: improve subagent UI display and interruption handling (#330)

Co-authored-by: Letta <noreply@letta.com>

src/cli/components/ToolCallMessageRich.tsx

@@ -1,5 +1,6 @@
 import { Box, Text } from "ink";
 import { memo } from "react";
+import { INTERRUPTED_BY_USER } from "../../constants";
 import { clipToolReturn } from "../../tools/manager.js";
 import { formatArgsDisplay } from "../helpers/formatArgsDisplay.js";
 import {
@@ -46,8 +47,14 @@ export const ToolCallMessage = memo(({ line }: { line: ToolCallLine }) => {
   const argsText = line.argsText ?? "...";
 
   // Task tool - handled by SubagentGroupDisplay, don't render here
+  // Exception: Cancelled/rejected Task tools should be rendered inline
+  // since they won't appear in SubagentGroupDisplay
   if (isTaskTool(rawName)) {
-    return null;
+    const isCancelledOrRejected =
+      line.phase === "finished" && line.resultOk === false;
+    if (!isCancelledOrRejected) {
+      return null;
+    }
   }
 
   // Apply tool name remapping
@@ -103,14 +110,14 @@ export const ToolCallMessage = memo(({ line }: { line: ToolCallLine }) => {
       );
     }
 
-    if (line.resultText === "Interrupted by user") {
+    if (line.resultText === INTERRUPTED_BY_USER) {
       return (
         <Box flexDirection="row">
           <Box width={prefixWidth} flexShrink={0}>
             <Text>{prefix}</Text>
           </Box>
           <Box flexGrow={1} width={contentWidth}>
-            <Text color={colors.status.interrupt}>Interrupted by user</Text>
+            <Text color={colors.status.interrupt}>{INTERRUPTED_BY_USER}</Text>
           </Box>
         </Box>
       );