26.9：直链下载 + 过期回收 + SHA512 去重 + 防盗链 + 媒体预览 + 文件夹上传提示

- 对象存储直链：S3 引擎 302 到限时预签名 URL（有效期钳位分享剩余时效），失败自动回落代理
- 过期回收：janitor 定时扫描 + 取件惰性回收 + 管理端手动触发（POST /admin/recycle/run），
  retention_days 最长存储时长；删除走引用计数（去重对象安全）
- SHA512 内容去重：三条上传链路落库后计算哈希，命中即复用旧对象并删除本次副本
- 下载防盗链：Referer 白名单（同源/空 Referer/通配域名放行），挂 /share/download
- 取件页图片/音频内联预览（下载地址直连，加载失败回退下载按钮）
- 文件夹上传：拖拽目录明确提示"建议压缩后上传"（webkitGetAsEntry 探测）
- 管理端设置卡「回收与下载安全」8 个新配置键（KVSchema + configKeys + UI + i18n）
- 前端产物重建并同步 server/web/dist 与 web-embed
- 文档：10-config 配置表、03-file-share 直链/防盗链/文件夹章节、07-admin 回收端点、openapi

web/src/api/share.ts

@@ -49,6 +49,7 @@ export async function getMetadata(code: string): Promise<ShareMetadata> {
     remainingDownloads:
       (pick<number>(raw, ['remaining_downloads', 'remainingDownloads', 'expired_count', 'expiredCount']) as number) ??
       null,
+    downloadUrl: (pick<string>(raw, ['download_url', 'downloadUrl']) as string) ?? null,
   }
 }
 

web/src/api/types.ts

@@ -27,6 +27,8 @@ export interface ShareMetadata {
   expiredCount: number | null
   usedCount: number
   remainingDownloads: number | null
+  /** 26.9：select 接口返回的下载地址（代理路径或 S3 预签名直链） */
+  downloadUrl?: string | null
 }
 
 export interface ShareTextResult {

web/src/components/FileDrop.vue

@@ -40,6 +40,12 @@ const acceptHint = computed(() => {
 function accept(f: File | null | undefined): void {
   error.value = ''
   if (!f) return
+  // 26.9：拒绝文件夹条目（webkitRelativePath 非空 = 来自文件夹选择）
+  if ((f as File & { webkitRelativePath?: string }).webkitRelativePath) {
+    error.value = t('drop.folderHint')
+    emit('update:modelValue', null)
+    return
+  }
   if (props.maxSize && f.size > props.maxSize) {
     error.value = t('drop.tooLarge', { size: formatBytes(f.size), limit: formatBytes(props.maxSize) })
     emit('update:modelValue', null)
@@ -48,9 +54,25 @@ function accept(f: File | null | undefined): void {
   emit('update:modelValue', f)
 }
 
+/** 26.9：拖拽条目里是否夹带目录（dataTransfer.files 对目录为空，须用 entries 探测） */
+function hasDirectory(items: DataTransferItemList | null | undefined): boolean {
+  if (!items) return false
+  for (let i = 0; i < items.length; i++) {
+    const entry = items[i]?.webkitGetAsEntry?.()
+    if (entry?.isDirectory) return true
+  }
+  return false
+}
+
 function onDrop(e: DragEvent): void {
   dragover.value = false
   if (props.disabled) return
+  // 26.9：拖入目录 → 明确提示"建议压缩后上传"（替代此前的静默忽略）
+  if (hasDirectory(e.dataTransfer?.items)) {
+    error.value = t('drop.folderHint')
+    emit('update:modelValue', null)
+    return
+  }
   accept(e.dataTransfer?.files?.[0])
 }
 

web/src/locales/en-US.ts

@@ -47,6 +47,9 @@ export default {
     close: 'Close',
     actions: 'Actions',
     all: 'All',
+    enabled: 'Enabled',
+    disabled: 'Disabled',
+    days: 'days',
     query: 'Query',
     reset: 'Reset',
     previousPage: 'Previous',
@@ -144,6 +147,8 @@ export default {
     loadingText: 'Fetching content…',
     copyContent: 'Copy content',
     downloadTxt: 'Download as .txt',
+    previewImage: 'Image preview',
+    previewAudio: 'Audio playback',
     downloaded: 'Download complete',
     downloadFailed: 'Download failed, please retry',
     copied: 'Content copied',
@@ -170,6 +175,7 @@ export default {
     remove: 'Remove',
     tooLarge: 'File size {size} exceeds the limit {limit}',
     typeHint: 'Allowed types: {types}',
+    folderHint: 'Folder upload is not supported. Please compress it into an archive first.',
   },
   docs: {
     searchPlaceholder: 'Search documentation…',
@@ -362,6 +368,24 @@ export default {
       uploadMinuteHint: 'Min 1, max {max}',
       uploadRate: 'Upload bandwidth (optional)',
       uploadRateHint: '0 = unlimited; MB/s; range 0~1024. Live-effective (admin reads latest KV each request)',
+      sectionRecycle: 'Recycle & Download Safety',
+      recycleHint: 'Expired-share recycling, retention limit, content dedup, direct download and hotlink protection',
+      recycleEnabled: 'Auto-recycle expired',
+      recycleEnabledHint: 'Periodically delete expired/exhausted shares together with their stored objects',
+      recycleInterval: 'Recycle scan interval',
+      recycleIntervalHint: '1~1440 minutes; accessing an expired share also triggers immediate recycling',
+      retentionDays: 'Max retention (days)',
+      retentionDaysHint: 'Shares older than this many days are recycled automatically; 0 = unlimited',
+      dedupEnabled: 'SHA512 dedup',
+      dedupEnabledHint: 'Identical files are stored once (multiple shares reference the same object)',
+      directDownload: 'Direct download',
+      directDownloadHint: '302 redirect to a presigned URL on S3-like engines; bytes bypass this server',
+      directLinkExpire: 'Direct link TTL',
+      directLinkExpireHint: '1~60 minutes (never longer than the share remains valid)',
+      hotlinkEnabled: 'Hotlink protection',
+      hotlinkEnabledHint: 'Validates Referer against a whitelist; empty Referer (direct visit) is allowed',
+      hotlinkWhitelist: 'Hotlink whitelist',
+      hotlinkWhitelistHint: 'Comma-separated domains, supports *.example.com; empty = same-site only',
       downloadRate: 'Download bandwidth (optional)',
       downloadRateHint: '0 = unlimited; MB/s; range 0~1024. S3 presigned direct upload cannot be throttled server-side',
       // —— v3: friendly units + storage engine ——

web/src/locales/zh-CN.ts

@@ -47,6 +47,9 @@ export default {
     close: '关闭',
     actions: '操作',
     all: '全部',
+    enabled: '开启',
+    disabled: '关闭',
+    days: '天',
     query: '查询',
     reset: '重置',
     previousPage: '上一页',
@@ -140,6 +143,8 @@ export default {
     loadingText: '正在获取内容…',
     copyContent: '复制内容',
     downloadTxt: '下载为 .txt',
+    previewImage: '图片预览',
+    previewAudio: '音频播放',
     downloaded: '下载完成',
     downloadFailed: '下载失败，请重试',
     copied: '内容已复制',
@@ -166,6 +171,7 @@ export default {
     remove: '移除',
     tooLarge: '文件大小 {size} 超过限制 {limit}',
     typeHint: '仅支持 {types}',
+    folderHint: '暂不支持文件夹上传，建议压缩后上传',
   },
   docs: {
     searchPlaceholder: '检索文档内容…',
@@ -356,6 +362,24 @@ export default {
       uploadMinuteHint: '最小 1，最大 {max}',
       uploadRate: '上行带宽（可选）',
       uploadRateHint: '0 = 不限速；单位 MB/s；范围 0~1024。修改后立即生效（管理端读最新 KV）',
+      sectionRecycle: '回收与下载安全',
+      recycleHint: '过期分享自动回收、存储时长上限、内容去重、直链下载与防盗链',
+      recycleEnabled: '过期自动回收',
+      recycleEnabledHint: '开启后定时清理已过期/次数耗尽的分享（含其存储对象）',
+      recycleInterval: '回收扫描间隔',
+      recycleIntervalHint: '范围 1~1440 分钟；取件时发现过期也会立即触发回收',
+      retentionDays: '最长存储时长',
+      retentionDaysHint: '上传超过该天数的分享将被自动回收；0 = 不限制',
+      dedupEnabled: 'SHA512 内容去重',
+      dedupEnabledHint: '相同内容的文件仅存储一份（多分享引用同一对象）',
+      directDownload: '直链下载',
+      directDownloadHint: 'S3 等对象存储引擎时 302 跳转到限时直链，文件不经过本站带宽',
+      directLinkExpire: '直链有效期',
+      directLinkExpireHint: '范围 1~60 分钟（不超过分享剩余时效）',
+      hotlinkEnabled: '下载防盗链',
+      hotlinkEnabledHint: '校验 Referer 白名单；空 Referer（直接访问）放行',
+      hotlinkWhitelist: '防盗链白名单',
+      hotlinkWhitelistHint: '逗号分隔域名，支持 *.example.com；空 = 仅本站域名放行',
       downloadRate: '下行带宽（可选）',
       downloadRateHint: '0 = 不限速；单位 MB/s；范围 0~1024。S3 预签名直传（客户端→S3）无法限速',
       // —— v3：单位友好化 + 存储引擎 ——

web/src/views/PickupView.vue

@@ -107,6 +107,35 @@ const remaining = computed(() => {
   if (m.remainingDownloads === null || m.remainingDownloads === undefined) return t('pickup.remainingUnlimited')
   return m.remainingDownloads < 0 ? t('pickup.remainingUnlimited') : t('pickup.remainingCount', { n: m.remainingDownloads })
 })
+
+// ===== 26.9：媒体内联预览（图片/音频）=====
+const IMAGE_EXT = ['png', 'jpg', 'jpeg', 'gif', 'webp', 'bmp', 'svg', 'avif']
+const AUDIO_EXT = ['mp3', 'wav', 'ogg', 'oga', 'm4a', 'flac', 'aac', 'opus']
+const IMAGE_PREVIEW_MAX = 30 * 1024 * 1024
+const AUDIO_PREVIEW_MAX = 100 * 1024 * 1024
+
+const mediaKind = computed<'image' | 'audio' | null>(() => {
+  const m = meta.value
+  if (!m || m.isText) return null
+  const name = (m.name || '').toLowerCase()
+  const dot = name.lastIndexOf('.')
+  if (dot < 0) return null
+  const ext = name.slice(dot + 1)
+  if (IMAGE_EXT.includes(ext) && m.size <= IMAGE_PREVIEW_MAX) return 'image'
+  if (AUDIO_EXT.includes(ext) && m.size <= AUDIO_PREVIEW_MAX) return 'audio'
+  return null
+})
+
+/** 媒体源：select 返回的 download_url（代理路径或 S3 直链）；缺失则不预览 */
+const mediaSrc = computed(() => {
+  if (!mediaKind.value) return ''
+  const url = meta.value?.downloadUrl
+  if (!url) return ''
+  return url.startsWith('/') ? new URL(url, location.origin).toString() : url
+})
+
+const previewFailed = ref(false)
+watch([mediaSrc, () => meta.value?.code], () => (previewFailed.value = false))
 </script>
 
 <template>
@@ -161,6 +190,27 @@ const remaining = computed(() => {
             </div>
           </div>
 
+          <!-- 26.9：图片/音频内联预览（加载失败自动隐藏回退下载） -->
+          <div v-if="mediaSrc && !previewFailed" class="media-preview">
+            <p class="hint" style="margin: 0 0 8px">
+              {{ mediaKind === 'image' ? t('pickup.previewImage') : t('pickup.previewAudio') }}
+            </p>
+            <img
+              v-if="mediaKind === 'image'"
+              :src="mediaSrc"
+              :alt="meta.name"
+              style="max-width: 100%; max-height: 360px; border-radius: 10px; display: block; margin: 0 auto"
+              @error="previewFailed = true"
+            />
+            <audio
+              v-else
+              controls
+              :src="mediaSrc"
+              style="width: 100%"
+              @error="previewFailed = true"
+            ></audio>
+          </div>
+
           <div v-if="downloadPercent !== null" style="margin: 16px 0 6px">
             <div class="progress"><i :style="{ width: `${downloadPercent}%` }"></i></div>
             <p class="hint">{{ t('pickup.downloading', { percent: downloadPercent }) }}</p>

web/src/views/admin/SettingsView.vue

@@ -43,6 +43,9 @@ const BACKGROUND_URL_MAX = 2048
 const UPLOAD_COUNT_MAX = 10000
 const UPLOAD_MINUTE_MAX = 1440
 const RATE_MAX_MB = 1024 // 1 GiB/s 上限（与后端 KVSchema 1<<30 字节对齐）
+// 26.9：回收与下载安全边界（与后端 KVSchema 一致）
+const RETENTION_DAYS_MAX = 3650
+const HOTLINK_WHITELIST_MAX = 2048
 
 const form = reactive({
   site_name: '',
@@ -65,6 +68,15 @@ const form = reactive({
   // 26.9：上下行带宽（前端友好单位 = MB/s；提交时换算为字节/秒）
   uploadRate: 0,
   downloadRate: 0,
+  // 26.9 回收与下载安全（interval/expire 前端友好单位 = 分钟；提交换算秒）
+  recycle_enabled: true,
+  recycle_interval_min: 30,
+  retention_days: 0,
+  dedup_enabled: true,
+  direct_download: true,
+  direct_link_expire_min: 15,
+  hotlink_enabled: false,
+  hotlink_whitelist: '',
 })
 
 // —— v3：友好单位状态（canonical 单位仍为秒/字节，换算在前端）——
@@ -169,6 +181,15 @@ async function load(): Promise<void> {
     // 26.9：带宽（KV 字节/秒 → UI MB/s，0 保留为不限）
     form.uploadRate = Math.round(toNum(pick<unknown>(cfg, ['upload_rate', 'uploadRate']), 0) / MB_BYTES)
     form.downloadRate = Math.round(toNum(pick<unknown>(cfg, ['download_rate', 'downloadRate']), 0) / MB_BYTES)
+    // 26.9：回收与下载安全（秒 → 分钟）
+    form.recycle_enabled = toNum(pick<unknown>(cfg, ['recycle_enabled']), 1) === 1
+    form.recycle_interval_min = Math.max(1, Math.round(toNum(pick<unknown>(cfg, ['recycle_interval']), 1800) / 60))
+    form.retention_days = toNum(pick<unknown>(cfg, ['retention_days']), 0)
+    form.dedup_enabled = toNum(pick<unknown>(cfg, ['dedup_enabled']), 1) === 1
+    form.direct_download = toNum(pick<unknown>(cfg, ['direct_download']), 1) === 1
+    form.direct_link_expire_min = Math.max(1, Math.round(toNum(pick<unknown>(cfg, ['direct_link_expire']), 900) / 60))
+    form.hotlink_enabled = toNum(pick<unknown>(cfg, ['hotlink_enabled']), 0) === 1
+    form.hotlink_whitelist = String(pick<string>(cfg, ['hotlink_whitelist']) ?? '')
     // v3：当前引擎（get 的 _engine_hint.storage_backend 或公开 config 的 storage_engine）
     const hint = pick<Record<string, unknown>>(cfg, ['_engine_hint'])
     const backend = hint ? String(pick<string>(hint, ['storage_backend']) ?? '') : ''
@@ -239,6 +260,15 @@ async function save(): Promise<void> {
       // 26.9：带宽（MB/s → 字节/秒；负数与 NaN 归 0）
       upload_rate: clamp(Number(form.uploadRate) || 0, 0, RATE_MAX_MB) * MB_BYTES,
       download_rate: clamp(Number(form.downloadRate) || 0, 0, RATE_MAX_MB) * MB_BYTES,
+      // 26.9：回收与下载安全（分钟 → 秒；开关 0/1）
+      recycle_enabled: form.recycle_enabled ? 1 : 0,
+      recycle_interval: clamp((Number(form.recycle_interval_min) || 30) * 60, 60, 86400),
+      retention_days: clamp(Number(form.retention_days) || 0, 0, RETENTION_DAYS_MAX),
+      dedup_enabled: form.dedup_enabled ? 1 : 0,
+      direct_download: form.direct_download ? 1 : 0,
+      direct_link_expire: clamp((Number(form.direct_link_expire_min) || 15) * 60, 60, 3600),
+      hotlink_enabled: form.hotlink_enabled ? 1 : 0,
+      hotlink_whitelist: form.hotlink_whitelist.trim().slice(0, HOTLINK_WHITELIST_MAX),
     })
     toast.success(t('admin.settings.saved'))
     await config.load() // 立即刷新导航 Logo / favicon / 站点名称 / 背景 / 页脚 / 通知
@@ -268,6 +298,14 @@ function restoreDefaults(): void {
   form.uploadMinute = 1
   form.uploadRate = 0
   form.downloadRate = 0
+  form.recycle_enabled = true
+  form.recycle_interval_min = 30
+  form.retention_days = 0
+  form.dedup_enabled = true
+  form.direct_download = true
+  form.direct_link_expire_min = 15
+  form.hotlink_enabled = false
+  form.hotlink_whitelist = ''
   // v3：单位状态复位
   saveTimeValue.value = 0
   saveTimeUnit.value = 'day'
@@ -785,6 +823,111 @@ onMounted(load)
         </div>
       </section>
 
+      <section class="card">
+        <h3 class="card-title">{{ t('admin.settings.sectionRecycle') }}</h3>
+        <p class="card-sub">{{ t('admin.settings.recycleHint') }}</p>
+        <div class="field-row">
+          <div class="field">
+            <label for="set-recycle-enabled">{{ t('admin.settings.recycleEnabled') }}</label>
+            <select id="set-recycle-enabled" v-model="form.recycle_enabled" class="input">
+              <option :value="true">{{ t('common.enabled') }}</option>
+              <option :value="false">{{ t('common.disabled') }}</option>
+            </select>
+            <p class="hint">{{ t('admin.settings.recycleEnabledHint') }}</p>
+          </div>
+          <div class="field">
+            <label for="set-recycle-interval">{{ t('admin.settings.recycleInterval') }}</label>
+            <div class="unit-row">
+              <input
+                id="set-recycle-interval"
+                v-model.number="form.recycle_interval_min"
+                class="input"
+                type="number"
+                :min="1"
+                :max="1440"
+                step="1"
+              />
+              <span class="unit-suffix">min</span>
+            </div>
+            <p class="hint">{{ t('admin.settings.recycleIntervalHint') }}</p>
+          </div>
+        </div>
+        <div class="field-row" style="margin-top: 14px">
+          <div class="field">
+            <label for="set-retention-days">{{ t('admin.settings.retentionDays') }}</label>
+            <div class="unit-row">
+              <input
+                id="set-retention-days"
+                v-model.number="form.retention_days"
+                class="input"
+                type="number"
+                :min="0"
+                :max="3650"
+                step="1"
+              />
+              <span class="unit-suffix">{{ t('common.days') }}</span>
+            </div>
+            <p class="hint">{{ t('admin.settings.retentionDaysHint') }}</p>
+          </div>
+          <div class="field">
+            <label for="set-dedup-enabled">{{ t('admin.settings.dedupEnabled') }}</label>
+            <select id="set-dedup-enabled" v-model="form.dedup_enabled" class="input">
+              <option :value="true">{{ t('common.enabled') }}</option>
+              <option :value="false">{{ t('common.disabled') }}</option>
+            </select>
+            <p class="hint">{{ t('admin.settings.dedupEnabledHint') }}</p>
+          </div>
+        </div>
+        <div class="field-row" style="margin-top: 14px">
+          <div class="field">
+            <label for="set-direct-download">{{ t('admin.settings.directDownload') }}</label>
+            <select id="set-direct-download" v-model="form.direct_download" class="input">
+              <option :value="true">{{ t('common.enabled') }}</option>
+              <option :value="false">{{ t('common.disabled') }}</option>
+            </select>
+            <p class="hint">{{ t('admin.settings.directDownloadHint') }}</p>
+          </div>
+          <div class="field">
+            <label for="set-direct-expire">{{ t('admin.settings.directLinkExpire') }}</label>
+            <div class="unit-row">
+              <input
+                id="set-direct-expire"
+                v-model.number="form.direct_link_expire_min"
+                class="input"
+                type="number"
+                :min="1"
+                :max="60"
+                step="1"
+              />
+              <span class="unit-suffix">min</span>
+            </div>
+            <p class="hint">{{ t('admin.settings.directLinkExpireHint') }}</p>
+          </div>
+        </div>
+        <div class="field-row" style="margin-top: 14px">
+          <div class="field">
+            <label for="set-hotlink-enabled">{{ t('admin.settings.hotlinkEnabled') }}</label>
+            <select id="set-hotlink-enabled" v-model="form.hotlink_enabled" class="input">
+              <option :value="true">{{ t('common.enabled') }}</option>
+              <option :value="false">{{ t('common.disabled') }}</option>
+            </select>
+            <p class="hint">{{ t('admin.settings.hotlinkEnabledHint') }}</p>
+          </div>
+          <div class="field">
+            <label for="set-hotlink-whitelist">{{ t('admin.settings.hotlinkWhitelist') }}</label>
+            <textarea
+              id="set-hotlink-whitelist"
+              v-model="form.hotlink_whitelist"
+              class="input"
+              rows="2"
+              maxlength="2048"
+              placeholder="a.com, b.org"
+            ></textarea>
+            <p class="hint">{{ t('admin.settings.hotlinkWhitelistHint') }}</p>
+          </div>
+        </div>
+      </section>
+
       <div class="save-row">
         <button class="btn" type="submit" :disabled="saving">
           <span v-if="saving" class="spin" aria-hidden="true"></span>