20260831 後台最新消息調整字數上限

app/Filament/Resources/NewsResource.php

                         ->columnSpanFull()
                         ->label("短文")
                         ->maxLength(84)
+                        ->extraInputAttributes([
+                            'oninput' => 'if (this.value.length > 84) { this.value = this.value.slice(0, 84); }',
+                        ])
                         ->reactive()
                         ->helperText(function (callable $get) {