fix: convert orphaned tool_results to text blocks after condensing

When condensing occurs after assistant sends tool_uses but before user responds,
the tool_use blocks get condensed away. User messages containing tool_results that
reference condensed tool_use_ids become orphaned and get filtered out by
getEffectiveApiHistory, causing user feedback to be lost.

This fix enhances the existing check in addToApiConversationHistory to detect when
the previous effective message is not an assistant and converts any tool_result
blocks to text blocks, preventing them from being filtered as orphans.

The conversion happens at the latest possible moment (message insertion) because:
- Tool results are created before we know if condensing will occur
- We need actual effective history state to make the decision
- This is the last checkpoint before orphan filtering happens

Author: daniel-lxs

src/core/task/Task.ts

@@ -1017,7 +1017,27 @@ export class Task extends EventEmitter<TaskEvents> implements TaskLike {
 			const effectiveHistoryForValidation = getEffectiveApiHistory(this.apiConversationHistory)
 			const lastEffective = effectiveHistoryForValidation[effectiveHistoryForValidation.length - 1]
 			const historyForValidation = lastEffective?.role === "assistant" ? effectiveHistoryForValidation : []
-			const validatedMessage = validateAndFixToolResultIds(message, historyForValidation)
+
+			// If the previous effective message is NOT an assistant, convert tool_result blocks to text blocks.
+			// This prevents orphaned tool_results from being filtered out by getEffectiveApiHistory.
+			// This can happen when condensing occurs after the assistant sends tool_uses but before
+			// the user responds - the tool_use blocks get condensed away, leaving orphaned tool_results.
+			let messageToAdd = message
+			if (lastEffective?.role !== "assistant" && Array.isArray(message.content)) {
+				messageToAdd = {
+					...message,
+					content: message.content.map((block) =>
+						block.type === "tool_result"
+							? {
+									type: "text" as const,
+									text: `Tool result:\n${typeof block.content === "string" ? block.content : JSON.stringify(block.content)}`,
+								}
+							: block,
+					),
+				}
+			}
+
+			const validatedMessage = validateAndFixToolResultIds(messageToAdd, historyForValidation)
 			const messageWithTs = { ...validatedMessage, ts: Date.now() }
 			this.apiConversationHistory.push(messageWithTs)
 		}