Show error feedback when clipboard copy fails

src/thread-modal.ts

@@ -48,7 +48,10 @@ export class ThreadModal extends Modal {
                 navigator.clipboard.writeText(tweet).then(() => {
                     copyBtn.setText("Copied");
                     setTimeout(() => copyBtn.setText("Copy"), 2000);
-                }).catch(() => {});
+                }).catch(() => {
+                    copyBtn.setText("Failed");
+                    setTimeout(() => copyBtn.setText("Copy"), 2000);
+                });
             });
         }
 
@@ -62,7 +65,10 @@ export class ThreadModal extends Modal {
                 navigator.clipboard.writeText(all).then(() => {
                     copyAllBtn.setText("Copied");
                     setTimeout(() => copyAllBtn.setText("Copy all"), 2000);
-                }).catch(() => {});
+                }).catch(() => {
+                    copyAllBtn.setText("Failed");
+                    setTimeout(() => copyAllBtn.setText("Copy all"), 2000);
+                });
             });
         }
     }