feat: deduplicate read_file history to optimize context length

Adds deduplicateReadFileHistory() method to Task class to retain only the latest read_file result per file, optimizing context length and token usage.

- Introduces deduplicateReadFileHistory() in Task class to keep only the latest read_file result for each file in apiConversationHistory
- Invoked in attemptApiRequest() to clean up history before making a new API request
- Iterates over apiConversationHistory to find and remove older read_file entries for the same file
- Ensures only the most recent read_file entry is retained, reducing context length and token usage

Co-authored-by: axb <qindi@staff.weibo.com>

src/core/task/Task.ts

@@ -1670,6 +1670,8 @@ export class Task extends EventEmitter<ClineEvents> {
 			profileThresholds = {},
 		} = state ?? {}
 
+		this.deduplicateReadFileHistory()
+
 		// Get condensing configuration for automatic triggers
 		const customCondensingPrompt = state?.customCondensingPrompt
 		const condensingApiConfigId = state?.condensingApiConfigId
@@ -1893,6 +1895,41 @@ export class Task extends EventEmitter<ClineEvents> {
 		yield* iterator
 	}
 
+	deduplicateReadFileHistory() {
+		for (let i = this.apiConversationHistory.length - 1; i >= 0; i--) {
+			const conversation = this.apiConversationHistory[i]
+
+			if (conversation.role !== "user") continue
+
+			const content = conversation.content
+			if (typeof content === "string") continue
+
+			const firstItem = content[0]
+			if (typeof firstItem === "string" || !("type" in firstItem) || firstItem.type !== "text") continue
+
+			const toolUseText = firstItem.text
+			if (!toolUseText || !toolUseText.startsWith("[read_file for ")) continue
+
+			for (let j = i - 1; j >= 0; j--) {
+				const prevConversation = this.apiConversationHistory[j]
+
+				if (prevConversation.role === "assistant") continue
+
+				const prevContent = prevConversation.content
+				if (typeof prevContent === "string") continue
+
+				const prevFirstItem = prevContent[0]
+				if (typeof prevFirstItem === "string" || !("type" in prevFirstItem) || prevFirstItem.type !== "text")
+					continue
+
+				if (prevFirstItem.text === toolUseText && prevContent.length === 3) {
+					prevContent.splice(1, 1)
+					break
+				}
+			}
+		}
+	}
+
 	// Checkpoints
 
 	public async checkpointSave(force: boolean = false) {