fix for retention logic

internal/domain/channel.go

@@ -634,6 +634,10 @@ const (
 	ChannelActionSuggestedPostApproval ChannelMessageActionType = "suggested_post_approval"
 	ChannelActionSuggestedPostSuccess  ChannelMessageActionType = "suggested_post_success"
 	ChannelActionSuggestedPostRefund   ChannelMessageActionType = "suggested_post_refund"
+	// ChannelActionCustomText 映射 messageActionCustomAction（stock TL 类型）：
+	// 当前唯一用途是把 storage retention 硬回收/主动淘汰清理掉的频道消息就地
+	// 转成这条通知（见 EditChannelMessageRequest.RetentionPurge）。
+	ChannelActionCustomText ChannelMessageActionType = "custom_text"
 )
 
 // ChannelMessageAction describes a service action without depending on tg.*.
@@ -678,6 +682,8 @@ type ChannelMessageAction struct {
 	SuggestedPostScheduleDate   int
 	SuggestedPostPrice          *SuggestedPostPrice
 	SuggestedPostPayerInitiated bool
+	// Text 仅 custom_text 服务消息使用（messageActionCustomAction.message）。
+	Text string
 }
 
 // ChannelMessage is a single stored message in a channel/supergroup.
@@ -1967,6 +1973,15 @@ type EditChannelMessageRequest struct {
 	// 仅当目标当前 media 仍是 ID==ExpectedWebPageID 的 pending 链接预览才替换。
 	WebPageResolve    bool
 	ExpectedWebPageID int64
+	// RetentionPurge 置位时为存储 retention 硬回收/主动淘汰的服务端内部编辑：
+	// 绕过普通的发送者/管理员编辑权限校验，仅由 internal/app/files 的
+	// retention purge 通知路径设置。见 EditMessageRequest.RetentionPurge。
+	RetentionPurge bool
+	// RetentionPurgeAction 与 RetentionPurge 搭配使用：频道消息的服务动作
+	// 存于独立的 Action 字段（不像私聊消息把服务动作折进 Media.Kind=service），
+	// 所以 retention 通知在频道侧必须整条消息转成一条新的服务消息（清空
+	// body/media，只设置这个 Action），而不是像私聊那样替换 Media。
+	RetentionPurgeAction *ChannelMessageAction
 }
 
 // EditChannelMessageResult describes one channel edit update.

internal/domain/media.go

@@ -591,6 +591,11 @@ const (
 	// 状态切换与关闭请求。会话级保护不能写入普通消息的 NoForwards 字段。
 	MessageServiceActionNoForwardsToggle  MessageServiceActionKind = "no_forwards_toggle"
 	MessageServiceActionNoForwardsRequest MessageServiceActionKind = "no_forwards_request"
+	// MessageServiceActionCustomText 映射 messageActionCustomAction（stock TL
+	// 类型，两端客户端已原生支持，无需任何 client 补丁）：服务端把纯文本状态
+	// 通知（当前唯一用途：storage retention 硬回收把已清理媒体的消息就地转成
+	// 这条通知）渲染成居中灰色系统气泡，而不是一次看起来像普通编辑的文本替换。
+	MessageServiceActionCustomText MessageServiceActionKind = "custom_text"
 )
 
 // MessagePhoneCallAction 是 messageActionPhoneCall 的协议中立载荷。
@@ -673,6 +678,8 @@ type MessageServiceAction struct {
 	RequestedPeer     *MessageRequestedPeerAction  `json:"requested_peer,omitempty"`
 	ChatThemeEmoticon string                       `json:"chat_theme_emoticon,omitempty"`
 	NoForwards        *MessageNoForwardsAction     `json:"no_forwards,omitempty"`
+	// Text 承载 MessageServiceActionCustomText 的固定通知文案（messageActionCustomAction.message）。
+	Text string `json:"text,omitempty"`
 }
 
 // MessageMedia 是一条消息媒体载荷的业务表示（落库为消息行上的 JSONB 快照）。

internal/domain/media_category.go

@@ -159,6 +159,26 @@ func classifyDocumentCategory(doc *Document) (MediaCategory, bool) {
 	}
 }
 
+// DocumentMediaCategory returns the single document-attribute category
+// (Video/Gif/Music/Voice/RoundVideo/File) for a document media payload, used
+// to populate the documents.category column alongside the shared media
+// index. Unlike ClassifyMediaCategories (which can also add unrelated
+// categories such as URL from message entities), this only ever answers "what
+// kind of document is this", returning MediaCategoryNone for a non-document
+// payload or for sticker/custom-emoji documents (they classify to nothing --
+// see classifyDocumentCategory). Zero new classification logic: reuses
+// classifyDocumentCategory exactly.
+func DocumentMediaCategory(media *MessageMedia) MediaCategory {
+	if media == nil || media.Kind != MessageMediaKindDocument {
+		return MediaCategoryNone
+	}
+	c, ok := classifyDocumentCategory(media.Document)
+	if !ok {
+		return MediaCategoryNone
+	}
+	return c
+}
+
 func hasURLEntity(entities []MessageEntity) bool {
 	for _, e := range entities {
 		if e.Type == MessageEntityURL || e.Type == MessageEntityTextURL || e.Type == MessageEntityEmail {

internal/domain/media_refs.go

@@ -1,5 +1,7 @@
 package domain
 
+import "time"
+
 // MediaKind identifies which table a media_references row points into.
 type MediaKind string
 
@@ -45,6 +47,16 @@ type OrphanCandidate struct {
 	OrphanedAt int64 // unix seconds
 }
 
+// EvictionCandidate is one document/photo still owning file_blobs bytes,
+// used by the active-eviction sweep (TELESRV_STORAGE_EVICTION_ENABLE) to pick
+// the oldest media overall across both tables once total physical storage
+// exceeds TELESRV_STORAGE_MAX_TOTAL_BYTES.
+type EvictionCandidate struct {
+	Kind      MediaKind
+	MediaID   int64
+	CreatedAt time.Time
+}
+
 // MediaRefTarget identifies one document/photo embedded in a message's media
 // snapshot.
 type MediaRefTarget struct {

internal/domain/message.go

@@ -555,6 +555,12 @@ type OutboxReadDateRequest struct {
 	ID          int
 }
 
+// RetentionPurgeNoticeText is the fixed notice text used for the
+// messageActionCustomAction (MessageServiceActionCustomText) service message
+// a storage-retention blob purge (hard mode or active eviction) turns a
+// message into once its underlying document/photo bytes are gone.
+const RetentionPurgeNoticeText = "This file was deleted by the server's storage retention policy."
+
 // EditMessageRequest 是账号视角下编辑一条已发送私聊消息的命令。
 // Media 非 nil 时整体替换消息媒体快照（当前唯一调用方是 live location 续报/停止，
 // rpc 层负责限定媒体种类）；nil 表示纯文本编辑。
@@ -589,6 +595,11 @@ type EditMessageRequest struct {
 	// 否则返回 ErrMessageNotModified（消息已删/已改/已解析）。
 	WebPageResolve    bool
 	ExpectedWebPageID int64
+	// RetentionPurge 置位时为存储 retention 硬回收/主动淘汰的服务端内部编辑：
+	// 绕过 authorEdit/viaBotEdit/WebPageResolve 之外的普通作者校验（回收发生
+	// 在任意账号的历史消息上，不是消息真正作者的操作），仅由
+	// internal/app/files 的 retention purge 通知路径设置。
+	RetentionPurge bool
 }
 
 // EditedMessageForUser 描述一次编辑对某个 owner 视角造成的影响。