fix: collect tool results from subagent messages with absent isMeta field (#23)

User messages in subagent JSONLs lack the isMeta field, defaulting to false.
An unconditional `continue` in the !isMeta branch skipped tool result
collection for these messages, causing all subagent tools to show
"No result received". Now we check for tool_result blocks before continuing,
allowing them to fall through to the result collection logic.

src/renderer/utils/displayItemBuilder.ts

@@ -423,16 +423,20 @@ export function buildDisplayItemsFromMessages(
         }
         continue;
       }
-      // Plain-text user message (subagent input prompt)
+      // Only treat as subagent input if there are NO tool_result blocks in this message
-      if (rawText.trim()) {
+      const hasToolResults =
+        Array.isArray(msg.content) &&
+        msg.content.some((b) => b.type === 'tool_result');
+      if (rawText.trim() && !hasToolResults) {
         displayItems.push({
           type: 'subagent_input',
           content: rawText.trim(),
           timestamp: msgTimestamp,
           tokenCount: estimateTokens(rawText),
         });
+        continue;
       }
-      continue;
+      // Fall through to tool result processing below if message has tool_results
     }
 
     if (msg.type === 'assistant' && Array.isArray(msg.content)) {

test/renderer/utils/displayItemBuilder.test.ts

@@ -0,0 +1,99 @@
+import { describe, expect, it } from 'vitest';
+import { buildDisplayItemsFromMessages } from '../../../src/renderer/utils/displayItemBuilder';
+import type { ParsedMessage } from '../../../src/main/types/messages';
+
+/**
+ * Helper to create a minimal ParsedMessage for testing.
+ */
+function makeMessage(overrides: Partial<ParsedMessage> & Pick<ParsedMessage, 'type' | 'content'>): ParsedMessage {
+  return {
+    uuid: `msg-${Math.random().toString(36).slice(2, 8)}`,
+    parentUuid: null,
+    timestamp: new Date('2025-01-01T00:00:00Z'),
+    isMeta: false,
+    isSidechain: false,
+    toolCalls: [],
+    toolResults: [],
+    ...overrides,
+  } as ParsedMessage;
+}
+
+describe('buildDisplayItemsFromMessages', () => {
+  describe('subagent tool results with isMeta=false', () => {
+    it('should collect tool results from user messages without isMeta field', () => {
+      // Simulates real subagent JSONL where user messages with tool_result
+      // blocks have isMeta absent (defaults to false after parsing).
+      const toolUseId = 'toolu_test123';
+
+      const assistantMsg = makeMessage({
+        uuid: 'assistant-1',
+        type: 'assistant',
+        content: [
+          {
+            type: 'tool_use',
+            id: toolUseId,
+            name: 'Bash',
+            input: { command: 'echo hello' },
+          },
+        ],
+        timestamp: new Date('2025-01-01T00:00:00Z'),
+      });
+
+      // This is the key scenario: user message with tool_result but isMeta: false
+      // (simulating subagent JSONL where isMeta field is absent)
+      const toolResultMsg = makeMessage({
+        uuid: 'user-result-1',
+        type: 'user',
+        isMeta: false,
+        content: [
+          {
+            type: 'tool_result',
+            tool_use_id: toolUseId,
+            content: 'hello\n',
+            is_error: false,
+          },
+        ],
+        toolResults: [
+          {
+            toolUseId: toolUseId,
+            content: 'hello\n',
+            isError: false,
+          },
+        ],
+        timestamp: new Date('2025-01-01T00:00:01Z'),
+      });
+
+      const items = buildDisplayItemsFromMessages([assistantMsg, toolResultMsg], []);
+
+      const toolItems = items.filter((item) => item.type === 'tool');
+      expect(toolItems).toHaveLength(1);
+
+      const tool = toolItems[0];
+      if (tool.type !== 'tool') throw new Error('Expected tool item');
+
+      // The critical assertion: result must be present, not orphaned
+      expect(tool.tool.isOrphaned).toBe(false);
+      expect(tool.tool.result).toBeDefined();
+      expect(tool.tool.result?.content).toBe('hello\n');
+      expect(tool.tool.name).toBe('Bash');
+    });
+
+    it('should still render subagent_input for plain text user messages without tool results', () => {
+      const userMsg = makeMessage({
+        uuid: 'user-input-1',
+        type: 'user',
+        isMeta: false,
+        content: 'Please run the tests',
+        toolResults: [],
+        timestamp: new Date('2025-01-01T00:00:00Z'),
+      });
+
+      const items = buildDisplayItemsFromMessages([userMsg], []);
+
+      const inputItems = items.filter((item) => item.type === 'subagent_input');
+      expect(inputItems).toHaveLength(1);
+      if (inputItems[0].type !== 'subagent_input') throw new Error('Expected subagent_input');
+      expect(inputItems[0].content).toBe('Please run the tests');
+    });
+  });
+});