Added a button to copy result. Plus note for password.

static/js/main.js

@@ -5,6 +5,7 @@ const salt = document.getElementById('salt');
 const hashBtn = document.getElementById('hashBtn');
 const result = document.getElementById('result');
 const clearBtn = document.getElementById('clearBtn');
+const resultBtn = document.getElementById('resultBtn');
 
 const MIN_PASS_LEN = 16;
 const MIN_SALT_LEN = 8;
@@ -54,3 +55,15 @@ clearBtn.addEventListener('click', () => {
     result.value = '';
 });
 
+resultBtn.addEventListener('click', async  () => {
+   if (!result.value) {
+      alert('Nothing to copy.');
+   }
+
+   try {
+      await navigator.clipboard.writeText(result.value);
+      alert('Copied to clipboard.');
+   } catch (err) {
+      alert('Failed to copy: ' + err);
+   }
+});