fix: Shell adapter history is not persisting

src/adapters/Shell.mjs

@@ -92,9 +92,15 @@ class Shell extends Adapter {
       await this.receive(message)
       this.#rl.prompt()
     })
+
     this.#rl.on('history', async (history) => {
-      await fs.promises.writeFile(historyPath, history.reverse().join('\n'))
+      if (history.length === 0) return
+      await fs.promises.appendFile(historyPath, `${history[0]}\n`)
     })
+
+    let existingHistory = (await fs.promises.readFile(historyPath, 'utf8')).split('\n')
+    existingHistory.forEach(line => this.#rl.history.push(line))
+
     try {
       this.#rl.prompt()
       this.emit('connected', this)