fix: remove undefined logger reference in SelfEvolveTool

src/tools/SelfEvolveTool.js

@@ -189,7 +189,6 @@ export class SelfEvolveTool {
 
       // ── STEP 2: File-level backup (survives even git corruption) ──
       const backupId = this._backupFile(absPath, relPath, checkpoint);
-      logger.info(`💾 File backup: ${backupId}`);
 
       // ── STEP 3: Apply patch ──
       const newContent = content.replace(oldCode, newCode);