feat(form): 增加表单栅格布局模块

新增 FormModules::grid 与 gridColumn，用统一方法生成 1 到 4 列的标准表单栅格，避免各业务表单重复拼接 layui 栅格类名。

在表单渲染壳层中注入标准样式，统一栅格列宽、字段间距、单行说明省略和自动补全下拉层样式，保证弹窗与页面模式展示一致。

补充 FormBuilderTest 覆盖可复用栅格布局、nowrap 说明文案和标准样式输出，防止后续表单布局能力回退。

plugin/think-library/src/builder/form/module/FormModules.php

@@ -13,6 +13,48 @@ use think\admin\builder\form\FormNode;
  */
 class FormModules
 {
+    /**
+     * 标准表单栅格容器.
+     */
+    public static function grid(FormNode $parent, int $columns = 2, string|array $class = '', int $space = 15): FormNode
+    {
+        $columns = self::normalizeGridColumns($columns);
+        $space = max(0, min(30, $space));
+        $node = $parent->div()->class([
+            'layui-row',
+            "layui-col-space{$space}",
+            'ta-form-grid',
+            "ta-form-grid-{$columns}",
+        ]);
+        if ($class !== '' && $class !== []) {
+            $node->class($class);
+        }
+        return $node;
+    }
+
+    /**
+     * 标准表单栅格列.
+     */
+    public static function gridColumn(FormNode $parent, int $columns = 2, string|array $class = ''): FormNode
+    {
+        $columns = self::normalizeGridColumns($columns);
+        $span = match ($columns) {
+            1 => 12,
+            2 => 6,
+            3 => 4,
+            default => 3,
+        };
+
+        $node = $parent->div()->class([
+            "layui-col-xs{$span}",
+            'ta-form-grid-col',
+        ]);
+        if ($class !== '' && $class !== []) {
+            $node->class($class);
+        }
+        return $node;
+    }
+
     /**
      * @param array<string, mixed> $config
      */
@@ -84,4 +126,9 @@ class FormModules
     {
         return htmlentities($content, ENT_QUOTES, 'UTF-8');
     }
+
+    private static function normalizeGridColumns(int $columns): int
+    {
+        return max(1, min(4, $columns));
+    }
 }

plugin/think-library/src/builder/form/render/FormShellRenderer.php

@@ -39,6 +39,7 @@ class FormShellRenderer
 
         $html = sprintf('<form %s>', $context->attrs($attrs));
         $html .= "\n\t" . sprintf('<div %s>', $context->attrs($bodyAttrs));
+        $html .= "\n\t\t" . $this->renderStandardStyle();
 
         if (count($content) > 0) {
             $html .= $context->renderChildren($content);
@@ -76,6 +77,7 @@ class FormShellRenderer
         $header = (new PageHeaderRenderer())->render(strval($schema['title'] ?? ''), $headerButtons);
         $form = sprintf('<form %s>', $context->attrs($attrs));
         $form .= "\n\t\t\t\t" . sprintf('<div %s>', $context->attrs($bodyAttrs));
+        $form .= "\n\t\t\t\t\t" . $this->renderStandardStyle();
 
         if (count($content) > 0) {
             $form .= "\n\t\t\t\t\t" . $context->renderChildren($content);
@@ -116,4 +118,30 @@ class FormShellRenderer
         $html .= "\n\t" . '</div>';
         return $html . "\n</div>";
     }
+
+    private function renderStandardStyle(): string
+    {
+        return <<<'HTML'
+<style data-form-builder-standard-style>
+.ta-form-grid{display:flex;flex-wrap:wrap;align-items:flex-start}
+.ta-form-grid>.ta-form-grid-col{box-sizing:border-box}
+.ta-form-grid-1>.ta-form-grid-col{width:100%!important;max-width:100%}
+.ta-form-grid-2>.ta-form-grid-col{width:50%!important;max-width:50%}
+.ta-form-grid-3>.ta-form-grid-col{width:33.333333%!important;max-width:33.333333%}
+.ta-form-grid-4>.ta-form-grid-col{width:25%!important;max-width:25%}
+.ta-form-grid>.ta-form-grid-col .layui-form-item{margin-bottom:14px}
+.ta-form-grid-compact>.ta-form-grid-col{padding-top:4px!important;padding-bottom:4px!important}
+.ta-form-grid-compact>.ta-form-grid-col .layui-form-item{margin-bottom:6px}
+.ta-form-grid-compact>.ta-form-grid-col .help-block{margin-top:2px;line-height:1.4}
+.ta-form-nowrap section>div:first-child p,
+.ta-form-nowrap .ta-form-grid-col .help-label,
+.ta-form-nowrap .ta-form-grid-col .help-block,
+.ta-form-grid.ta-form-nowrap .help-label,
+.ta-form-grid.ta-form-nowrap .help-block{display:block;max-width:100%;overflow:hidden;white-space:nowrap;text-overflow:ellipsis}
+.ta-form-autocompleter{top:58px;z-index:19892000;min-width:100%;border-radius:0 0 6px 6px;box-shadow:0 8px 24px rgba(15,23,42,.14)}
+.ta-form-autocompleter .autocompleter-list{max-height:220px;overflow-y:auto;background:#fff}
+.ta-form-autocompleter .autocompleter-item{overflow:hidden;white-space:nowrap;text-overflow:ellipsis}
+</style>
+HTML;
+    }
 }

plugin/think-library/tests/FormBuilderTest.php

@@ -25,6 +25,7 @@ use think\admin\Controller;
 use think\admin\builder\form\FormBuilder;
 use think\admin\builder\form\FormComponents;
 use think\admin\builder\form\FormChoiceField;
+use think\admin\builder\form\module\FormModules;
 use think\admin\builder\form\FormSelectField;
 use think\admin\builder\form\FormTextField;
 use think\admin\builder\form\FormUploadField;
@@ -348,6 +349,38 @@ class FormBuilderTest extends TestCase
         $this->assertStringContainsString('data-builder-modules=', $html);
     }
 
+    public function testFormModulesCanRenderReusableGridLayout(): void
+    {
+        $builder = $this->newBuilder();
+        $builder->define(function ($form) {
+            $form->class('ta-form-nowrap');
+            FormModules::section($form, [
+                'title' => '布局',
+                'description' => '描述信息保持单行显示。',
+            ], function ($section) {
+                $grid = FormModules::grid($section, 3, 'profile-grid');
+                FormModules::gridColumn($grid, 3)->fields(function ($fields) {
+                    $fields->text('nickname', '用户名称', 'Nickname', true, '单行说明');
+                });
+                FormModules::gridColumn($grid, 3)->fields(function ($fields) {
+                    $fields->text('email', '联系邮箱', 'Email');
+                });
+                FormModules::gridColumn($grid, 3)->fields(function ($fields) {
+                    $fields->text('phone', '联系电话', 'Phone');
+                });
+            });
+        })->build();
+
+        $html = $this->invokePrivate($builder, '_buildFormModal');
+
+        $this->assertStringContainsString('data-form-builder-standard-style', $html);
+        $this->assertStringContainsString('ta-form-nowrap', $html);
+        $this->assertStringContainsString('layui-row layui-col-space15 ta-form-grid ta-form-grid-3 profile-grid', $html);
+        $this->assertStringContainsString('layui-col-xs4 ta-form-grid-col', $html);
+        $this->assertStringContainsString('width:33.333333%!important', $html);
+        $this->assertStringContainsString('white-space:nowrap', $html);
+    }
+
     public function testPageModeCanRenderTitleAndDefaultPadding(): void
     {
         $builder = $this->newBuilder('form', 'page');