fix(submit): make the draft chain survive continuous writing, reloads and flaky networks

Autosave only ran after 4s of idle, and every keystroke reset that timer, so a
writer who never stopped had zero saves (measured: 15s of typing = 0 requests).
Saving also never rebound the URL, so a new draft could not be found again after
a reload, the local backup was cleared on every autosave, and a failed save had
no retry and stayed failed once the network came back.

Client
- autosave: keep the idle debounce but add a 30s max-wait window that is not
  reset by further keystrokes, and retry failures at 5s / 15s / 60s
- bind `?edit=<id>` into the URL once the server returns a post id, so reloads,
  new tabs and history all reopen the same draft
- only clear the local backup when the save settled and nothing changed since
- key the local backup by draft id instead of the constant `jio-studio-0`
- restore snapshots through hydrateBlocks so code blocks come back editable
- never disable publish while an autosave is in flight, and mark autosave
  states separately (自动保存中… / 已自动保存 / 自动保存失败，将重试)
- on 409, adopt the server rev and tell the author instead of failing silently
- status bar reports the real save state instead of a bogus Markdown hint

Server
- draft saves no longer rewrite the lifecycle: pending / future / publish /
  private posts keep their status, so an autosave cannot pull a submitted post
  out of the review queue
- drafts and autosaves stop consuming the publish flood quota, which is meant to
  cap actual publishing (measured: 4 drafts used to burn 4 slots)
- autosave skips wp_save_post_revision for both plain drafts and submission
  versions; manual saves and submits still create a revision to roll back to
- media-only drafts (image / table / code / hr) count as content
- the response now carries the resulting status so the client can tell
  "just submitted" from "still under review"

Tests cover the max-wait window, retry schedule, URL binding, backup clearing,
status labelling and every server-side draft rule.

src/Core/CreatorRest.php

@@ -235,6 +235,7 @@ final class CreatorRest {
 				'content'  => $payload['content'],
 				'base_rev' => absint($request->get_param('rev')),
 				'snapshot' => $this->snapshot_from_payload($payload),
+				'autosave' => $is_auto,
 			], false);
 			if (is_wp_error($result)) {
 				return $result;
@@ -252,6 +253,7 @@ final class CreatorRest {
 			'tags'         => implode(',', array_map('strval', $payload['tags'])),
 			'featured_data'=> $payload['featured'],
 			'schedule'     => $payload['schedule'],
+			'autosave'     => $is_auto,
 		];
 		foreach ($payload['custom'] as $key => $value) {
 			$data['cf_' . sanitize_key((string) $key)] = $value;

src/Core/FrontSubmitSave.php

@@ -17,7 +17,7 @@ trait FrontSubmitSave {
      *
      * @param array<string, mixed> $data Request payload.
      * @param string               $action posts_save|posts_draft
-     * @return array{success:bool,message:string,post_id?:int,url?:string,goto?:string,reload?:bool,time?:string,posts_id?:int}
+     * @return array{success:bool,message:string,post_id?:int,url?:string,goto?:string,reload?:bool,time?:string,posts_id?:int,status?:string}
      */
     public function persist(array $data, string $action = 'posts_save'): array {
         $user_id   = get_current_user_id();
@@ -26,6 +26,8 @@ trait FrontSubmitSave {
         $is_guest  = $user_id <= 0;
         $is_edit   = $posts_id > 0;
         $is_draft  = $action === 'posts_draft';
+        // 自动保存是后台动作：不建版本、不扣防刷配额、不改动审核状态。
+        $is_auto   = $is_draft && !empty($data['autosave']);
 
         if (empty($settings['enabled'])) {
             return ['success' => false, 'message' => __('投稿功能已关闭', 'jio')];
@@ -73,7 +75,9 @@ trait FrontSubmitSave {
             if (trim(wp_strip_all_tags($content)) === '') {
                 return ['success' => false, 'message' => __('还未填写任何内容', 'jio')];
             }
-        } elseif ($title === '' && trim(wp_strip_all_tags($content)) === '') {
+        } elseif ($title === '' && !$this->draft_has_content($content)) {
+            // 图片 / 表格 / 代码块这类媒体块即使没有文字也算草稿内容，
+            // 只贴了一张图的草稿不能被判成「什么都没写」。
             return ['success' => false, 'message' => __('请先写点什么再保存', 'jio')];
         }
 
@@ -126,7 +130,9 @@ trait FrontSubmitSave {
         }
 
         // [防刷机制]发布限制（后台「扩展&增强 → 网站安全」），管理员不受限。
-        if (!$is_edit && !current_user_can('manage_options') && class_exists('\Jio\Extensions\SecurityHardening')) {
+        // 草稿与自动保存不计数：配额防的是刷发布，把写作中的保存也算进去会让
+        // 正常写一篇长文就把额度用光。只有正式投稿（posts_save）计一次。
+        if (!$is_draft && !$is_edit && !current_user_can('manage_options') && class_exists('\Jio\Extensions\SecurityHardening')) {
             $security = \Jio\Settings\ExtensionRuntime::get_security_settings();
             $brush_subject = $is_guest
                 ? (string) (function_exists('jio_get_client_ip') ? jio_get_client_ip() : ($_SERVER['REMOTE_ADDR'] ?? ''))
@@ -149,6 +155,13 @@ trait FrontSubmitSave {
                     $status      = 'future';
                 }
             }
+        } elseif ($is_edit) {
+            // 草稿动作不能改写已有文章的生命周期：自动保存发生在投稿 / 审核期间时，
+            // 把 pending 或 future 直接写成 draft 会让文章悄悄掉出审核队列与排期。
+            $current_status = (string) get_post_status($posts_id);
+            $status = in_array($current_status, ['pending', 'future', 'publish', 'private'], true)
+                ? $current_status
+                : 'draft';
         }
 
         // Paid fields are validated before anything is written, so an invalid
@@ -193,7 +206,15 @@ trait FrontSubmitSave {
 
         if ($is_edit) {
             $postarr['ID'] = $posts_id;
+            if ($is_auto) {
+                // 自动保存每隔几秒就可能落一次，逐次建 revision 会把版本表撑到几百条。
+                // 版本只留给手动「保存草稿」与正式投稿，自动保存静默覆盖当前版本。
+                remove_action('post_updated', 'wp_save_post_revision');
+            }
             $in_id = wp_update_post($postarr, true);
+            if ($is_auto) {
+                add_action('post_updated', 'wp_save_post_revision');
+            }
         } else {
             $postarr['post_author'] = $author_id;
             $in_id = wp_insert_post($postarr, true);
@@ -238,6 +259,7 @@ trait FrontSubmitSave {
             'post_id'  => (int) $in_id,
             'posts_id' => (int) $in_id,
             'url'      => $url,
+            'status'   => $status,
         ];
 
         switch ($status) {
@@ -254,8 +276,12 @@ trait FrontSubmitSave {
                 }
                 break;
             case 'pending':
-                $send['message'] = __('内容已提交，正在等待审核', 'jio');
-                if ($user_id > 0 && function_exists('jio_get_user_home_url')) {
+                // 自动保存落到待审文章上时不是「刚提交」，文案与跳转都不能再走提交流程。
+                $send['message'] = $is_draft
+                    ? __('已保存，文章仍在审核队列中', 'jio')
+                    : __('内容已提交，正在等待审核', 'jio');
+                $send['time'] = current_time('mysql');
+                if (!$is_draft && $user_id > 0 && function_exists('jio_get_user_home_url')) {
                     $send['reload'] = true;
                     $send['goto']   = add_query_arg(
                         ['tab' => 'post', 'post_status' => 'pending'],
@@ -263,6 +289,16 @@ trait FrontSubmitSave {
                     );
                 }
                 break;
+            case 'publish':
+            case 'private':
+                // 已发布文章的草稿保存不能触发「文章已发布」与整页跳转。
+                $send['message'] = $is_draft ? __('已保存线上文章', 'jio') : __('文章已发布', 'jio');
+                $send['time']    = current_time('mysql');
+                if (!$is_draft) {
+                    $send['reload'] = true;
+                    $send['goto']   = $url;
+                }
+                break;
             case 'draft':
                 $send['message'] = __('草稿已保存', 'jio');
                 $send['time']    = current_time('mysql');
@@ -344,6 +380,19 @@ trait FrontSubmitSave {
         return strlen($text);
     }
 
+    /**
+     * 草稿是否已经有可保存的内容。
+     *
+     * 纯文字的草稿看文字，图片 / 表格 / 代码块 / 分割线这类块即使没有文字也算内容；
+     * 与前端 `plainText` + 块级元素判断保持同一口径，避免两边对「空草稿」结论不同。
+     */
+    private function draft_has_content(string $content): bool {
+        if (trim(wp_strip_all_tags($content)) !== '') {
+            return true;
+        }
+        return (bool) preg_match('/<(?:img|table|pre|hr|iframe|video|audio|figure)\b/i', $content);
+    }
+
     /**
      * @param array<string,mixed> $data
      * @param array<string,mixed> $settings

src/Core/SubmissionVersion.php

@@ -192,7 +192,7 @@ final class SubmissionVersion {
 	/**
 	 * 创建或更新作者的工作版本。
 	 *
-	 * @param array{title?:string,content?:string,excerpt?:string,snapshot?:array<string,mixed>,base_rev?:int} $data
+	 * @param array{title?:string,content?:string,excerpt?:string,snapshot?:array<string,mixed>,base_rev?:int,autosave?:bool} $data
 	 * @return array{success:bool,message?:string,version_id?:int,rev?:int,conflict?:bool}|\WP_Error
 	 */
 	public function save_working(int $source_id, int $user_id, array $data, bool $submit = false) {
@@ -265,7 +265,16 @@ final class SubmissionVersion {
 			'post_excerpt' => $excerpt,
 			'post_status'  => $next_status === self::STATUS_PENDING ? 'pending' : 'draft',
 		];
+		// 自动保存不建 revision：几秒一次地写版本表会把改稿记录撑满，
+		// 需要回滚的节点由手动保存与提交产生。
+		$is_auto = !empty($data['autosave']);
+		if ($is_auto) {
+			remove_action('post_updated', 'wp_save_post_revision');
+		}
 		$updated = wp_update_post($update, true);
+		if ($is_auto) {
+			add_action('post_updated', 'wp_save_post_revision');
+		}
 		if (is_wp_error($updated)) {
 			return new \WP_Error('jio_version_failed', $updated->get_error_message(), ['status' => 500]);
 		}