Fix tool group spacing by detecting subsequent renderable blocks

Add logic to check for renderable blocks after tool groups to conditionally
apply bottom margin. This prevents unnecessary spacing at the end of messages
while maintaining proper separation between tool groups and other content.

Author: brandonkachen

cli/src/components/message-block.tsx

@@ -637,14 +637,33 @@ export const MessageBlock = ({
           Boolean,
         ) as React.ReactNode[]
         if (nonNullGroupNodes.length > 0) {
+          // Check for any subsequent renderable blocks without allocating a slice
+          let hasRenderableAfter = false
+          for (let j = i; j < sourceBlocks.length; j++) {
+            const b = sourceBlocks[j] as any
+            if (b.type === 'tool') {
+              if ((b as any).toolName !== 'end_turn') {
+                hasRenderableAfter = true
+                break
+              }
+            } else if (
+              b.type === 'text' ||
+              b.type === 'html' ||
+              b.type === 'agent' ||
+              b.type === 'agent-list'
+            ) {
+              hasRenderableAfter = true
+              break
+            }
+          }
           nodes.push(
             <box
               key={`${messageId}-tool-group-${start}`}
               style={{
                 flexDirection: 'column',
                 gap: 0,
                 marginTop: 1,
-                marginBottom: 1,
+                marginBottom: hasRenderableAfter ? 1 : 0,
               }}
             >
               {nonNullGroupNodes}