refactor: Simplify log file initialization and clear log on new chat (#1982)

- Updated `ensureInitialized` method in `LogFileManager` to start with an empty buffer, removing unnecessary file reading logic.
- Integrated log clearing functionality in `handleNewChat` to ensure a fresh start for each chat session.

src/components/Chat.tsx

@@ -33,6 +33,7 @@ import { useChatFileDrop } from "@/hooks/useChatFileDrop";
 import { getAIResponse } from "@/langchainStream";
 import ChainManager from "@/LLMProviders/chainManager";
 import { clearRecordedPromptPayload } from "@/LLMProviders/chainRunner/utils/promptPayloadRecorder";
+import { logFileManager } from "@/logFileManager";
 import CopilotPlugin from "@/main";
 import { useIsPlusUser } from "@/plusUtils";
 import { updateSetting, useSettingsValue } from "@/settings/model";
@@ -574,6 +575,7 @@ const ChatInternal: React.FC<ChatProps & { chatInput: ReturnType<typeof useChatI
 
   const handleNewChat = useCallback(async () => {
     clearRecordedPromptPayload();
+    await logFileManager.clear();
     handleStopGenerating(ABORT_REASON.NEW_CHAT);
 
     // Analyze chat messages for memory if enabled

src/logFileManager.ts

@@ -30,32 +30,11 @@ class LogFileManager {
     return "copilot/copilot-log.md"; // under copilot/
   }
 
-  /** Ensure buffer is loaded with up to last 500 lines from existing file. */
+  /** Ensure the log manager is initialized. Always starts with an empty buffer. */
   private async ensureInitialized() {
     if (this.initialized) return;
-    try {
-      if (!this.hasVault()) {
-        this.initialized = true;
-        return;
-      }
-      const path = this.getLogPath();
-      const exists = await app.vault.adapter.exists(path);
-      if (exists) {
-        const content = await app.vault.adapter.read(path);
-        // Normalize line endings and split
-        const lines = content.split(/\r?\n/).filter((l) => l.length > 0);
-        if (lines.length > this.maxLines) {
-          this.buffer = lines.slice(lines.length - this.maxLines);
-        } else {
-          this.buffer = lines;
-        }
-      }
-    } catch {
-      // Ignore read errors; start fresh
-      this.buffer = [];
-    } finally {
-      this.initialized = true;
-    }
+    // Start with empty buffer - log file is only an export artifact
+    this.initialized = true;
   }
 
   private hasVault(): boolean {

src/main.ts

@@ -468,6 +468,7 @@ export default class CopilotPlugin extends Plugin {
 
   async handleNewChat() {
     clearRecordedPromptPayload();
+    await logFileManager.clear();
 
     // Analyze chat messages for memory if enabled
     if (getSettings().enableRecentConversations) {