fix: don't truncate all history when max is hit

truncate a smaller amount of the oldest entries

src/lib/history.mjs

@@ -1,6 +1,9 @@
 import fs from 'fs';
 import path from 'path';
 
+const MAX_ITEMS = 1000; // max entries in history
+const TRUNCATE_AMOUNT = 200; // count of entries to remove when max is hit
+
 export default class History {
   constructor() {
     this.filePath = path.resolve('data', 'history.json');
@@ -20,9 +23,11 @@ export default class History {
     // prevent duplicate entries
     if (this.get(doc.id)) return;
 
-    // add doc to history, truncate as needed
+    // add doc to history
     this.db.push(doc);
-    if (this.db.length > 1000) this.db.splice(0, 1000);
+
+    // truncate as needed, removing first TRUNCATE_AMOUNT entries from the array
+    if (this.db.length > MAX_ITEMS) this.db.splice(0, TRUNCATE_AMOUNT);
 
     // write the updated content to the file
     fs.writeFileSync(this.filePath, JSON.stringify(this.db), { encoding: 'utf8' });