fix(channels): declare managed media cleanup policy

Explicitly mark downloaded and managed channel media as delete-on-cleanup so media ownership is visible at each registration site.

Refs #1886

pkg/channels/discord/discord.go

@@ -398,6 +398,7 @@ func (c *DiscordChannel) handleMessage(s *discordgo.Session, m *discordgo.Messag
 			ref, err := store.Store(localPath, media.MediaMeta{
 				Filename:      filename,
 				Source:        "discord",
+				CleanupPolicy: media.CleanupPolicyDeleteOnCleanup,
 			}, scope)
 			if err == nil {
 				return ref

pkg/channels/feishu/feishu_64.go

@@ -727,6 +727,7 @@ func (c *FeishuChannel) downloadResource(
 	ref, err := store.Store(localPath, media.MediaMeta{
 		Filename:      filename,
 		Source:        "feishu",
+		CleanupPolicy: media.CleanupPolicyDeleteOnCleanup,
 	}, scope)
 	if err != nil {
 		logger.ErrorCF("feishu", "Failed to store downloaded resource", map[string]any{

pkg/channels/line/line.go

@@ -303,6 +303,7 @@ func (c *LINEChannel) processEvent(event lineEvent) {
 			ref, err := store.Store(localPath, media.MediaMeta{
 				Filename:      filename,
 				Source:        "line",
+				CleanupPolicy: media.CleanupPolicyDeleteOnCleanup,
 			}, scope)
 			if err == nil {
 				return ref

pkg/channels/matrix/matrix.go

@@ -692,6 +692,9 @@ func (c *MatrixChannel) extractInboundMedia(
 
 func (c *MatrixChannel) storeMedia(localPath string, meta media.MediaMeta, scope string) string {
 	if store := c.GetMediaStore(); store != nil {
+		if meta.CleanupPolicy == "" {
+			meta.CleanupPolicy = media.CleanupPolicyDeleteOnCleanup
+		}
 		ref, err := store.Store(localPath, meta, scope)
 		if err == nil {
 			return ref

pkg/channels/onebot/onebot.go

@@ -751,6 +751,7 @@ func (c *OneBotChannel) parseMessageSegments(
 			ref, err := store.Store(localPath, media.MediaMeta{
 				Filename:      filename,
 				Source:        "onebot",
+				CleanupPolicy: media.CleanupPolicyDeleteOnCleanup,
 			}, scope)
 			if err == nil {
 				return ref

pkg/channels/qq/qq.go

@@ -673,6 +673,7 @@ func (c *QQChannel) extractInboundAttachments(
 				Filename:      qqAttachmentFilename(attachment),
 				ContentType:   attachment.ContentType,
 				Source:        "qq",
+				CleanupPolicy: media.CleanupPolicyDeleteOnCleanup,
 			}, scope)
 			if err == nil {
 				return ref

pkg/channels/slack/slack.go

@@ -329,6 +329,7 @@ func (c *SlackChannel) handleMessageEvent(ev *slackevents.MessageEvent) {
 			ref, err := store.Store(localPath, media.MediaMeta{
 				Filename:      filename,
 				Source:        "slack",
+				CleanupPolicy: media.CleanupPolicyDeleteOnCleanup,
 			}, scope)
 			if err == nil {
 				return ref

pkg/channels/telegram/telegram.go

@@ -563,6 +563,7 @@ func (c *TelegramChannel) handleMessage(ctx context.Context, message *telego.Mes
 			ref, err := store.Store(localPath, media.MediaMeta{
 				Filename:      filename,
 				Source:        "telegram",
+				CleanupPolicy: media.CleanupPolicyDeleteOnCleanup,
 			}, scope)
 			if err == nil {
 				return ref

pkg/channels/wecom/aibot_ws.go

@@ -1220,6 +1220,7 @@ func (c *WeComAIBotWSChannel) storeWSMedia(
 	ref, err := store.Store(tmpPath, media.MediaMeta{
 		Filename:      msgID + ext,
 		Source:        "wecom_aibot",
+		CleanupPolicy: media.CleanupPolicyDeleteOnCleanup,
 	}, scope)
 	if err != nil {
 		os.Remove(tmpPath)

pkg/channels/weixin/media.go

@@ -294,6 +294,7 @@ func (c *WeixinChannel) storeInboundBytes(
 		Filename:      filename,
 		ContentType:   contentType,
 		Source:        "weixin",
+		CleanupPolicy: media.CleanupPolicyDeleteOnCleanup,
 	}, basechannels.BuildMediaScope("weixin", chatID, messageID))
 	if err != nil {
 		os.Remove(tmpPath)