feat: restore sablog browse modes and clean imported HTML

Keep the public site readable after import (nbsp, highlighter, wrapping code, compact pager) and finish the admin extras already in this tree: sticky levels, preview, page cache, and live llms.txt.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/Blog/Support/HomeViewMode.php

@@ -0,0 +1,69 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Blog\Support;
+
+use Illuminate\Http\Request;
+
+/**
+ * Homepage / list browse mode, matching old SaBlog 标准 | 列表.
+ */
+class HomeViewMode
+{
+    public const LIST = 'list';
+
+    public const FULL = 'full';
+
+    public const COOKIE = 'll_home_view';
+
+    /**
+     * @return array<string, string>
+     */
+    public static function options(): array
+    {
+        return [
+            self::LIST => '列表',
+            self::FULL => '标准',
+        ];
+    }
+
+    public static function isValid(mixed $value): bool
+    {
+        return is_string($value) && in_array($value, [self::LIST, self::FULL], true);
+    }
+
+    public static function resolve(?Request $request = null): string
+    {
+        $request ??= request();
+
+        foreach ([
+            $request->query('view'),
+            $request->cookie(self::COOKIE),
+            blog_setting('home_view_mode', config('blog.home_view_mode', self::LIST)),
+        ] as $value) {
+            if (self::isValid($value)) {
+                return $value;
+            }
+        }
+
+        return self::LIST;
+    }
+
+    public static function current(): string
+    {
+        $request = request();
+        $mode = self::resolve($request);
+
+        if (self::isValid($request->query('view'))) {
+            cookie()->queue(cookie(self::COOKIE, (string) $request->query('view'), 60 * 24 * 30));
+        }
+
+        return $mode;
+    }
+
+    public static function url(string $mode): string
+    {
+        return request()->fullUrlWithQuery(['view' => $mode]);
+    }
+}