fix(channel,attachment): channel quality refactor & attachment pipeline fixes (#349)

* feat(channel): add DingTalk channel adapter

- Add DingTalk channel adapter (`internal/channel/adapters/dingtalk/`) using dingtalk-stream-sdk-go, supporting inbound message receiving and outbound text/markdown reply
- Register DingTalk adapter in cmd/agent and cmd/memoh
- Add go.mod dependency: github.com/memohai/dingtalk-stream-sdk-go
- Add Dingtalk and Wecom SVG icons and Vue components to @memohai/icon
- Refactor existing icon components to remove redundant inline wrappers
- Add `channelTypeDisplayName` util for consistent channel label resolution
- Add DingTalk/WeCom i18n entries (en/zh) for types and typesShort
- Extend channel-icon, bot-channels, channel-settings-panel to support dingtalk/wecom
- Use channelTypeDisplayName in profile page to replace ad-hoc i18n lookup

* fix(channel,attachment): channel quality refactor & attachment pipeline fixes

Channel module:
- Fix RemoveAdapter not cleaning connectionMeta (stale status leak)
- Fix preparedAttachmentTypeFromMime misclassifying image/gif
- Fix sleepWithContext time.After goroutine/timer leak
- Export IsDataURL/IsHTTPURL/IsDataPath, dedup across packages
- Cache OutboundPolicy in managerOutboundStream to avoid repeated lookups
- Split OutboundAttachmentStore: extract ContainerAttachmentIngester interface
- Add ManagerOption funcs (WithInboundQueueSize, WithInboundWorkers, WithRefreshInterval)
- Add thread-safety docs on OutboundStream / managerOutboundStream
- Add debug logs on successful send/edit paths
- Expand outbound_prepare_test.go with 21 new cases
- Convert no-receiver adapter helpers to package-level funcs; drop unused params

DingTalk adapter:
- Implement AttachmentResolver: download inbound media via /v1.0/robot/messageFiles/download
- Fix pure-image inbound messages failing due to missing resolver

Attachment pipeline:
- Fix images invisible to LLM in pipeline (DCP) path: inject InlineImages into
  last user message when cfg.Query is empty
- Fix public_url fallback: skip direct URL-to-LLM when ContentHash is set,
  always prefer inlined persisted asset
- Inject path: carry ImageParts through agent.InjectMessage; inline persisted
  attachments in resolver inject goroutine so mid-stream images reach the model
- Fix ResolveMime for images: prefer content-sniffed MIME over platform-declared
  MIME (fixes Feishu sending image/png header for actual JPEG content → API 400)

internal/channel/adapters/feishu/stream.go

@@ -40,7 +40,7 @@ type feishuOutboundStream struct {
 	closed        atomic.Bool
 }
 
-func (s *feishuOutboundStream) Push(ctx context.Context, event channel.StreamEvent) error {
+func (s *feishuOutboundStream) Push(ctx context.Context, event channel.PreparedStreamEvent) error {
 	if s == nil || s.adapter == nil {
 		return errors.New("feishu stream not configured")
 	}
@@ -90,26 +90,28 @@ func (s *feishuOutboundStream) Push(ctx context.Context, event channel.StreamEve
 		if len(event.Attachments) == 0 {
 			return nil
 		}
-		media := channel.Message{
-			Attachments: event.Attachments,
-		}
-		return s.adapter.Send(ctx, s.cfg, channel.OutboundMessage{
-			Target:  s.target,
-			Message: media,
+		return s.adapter.Send(ctx, s.cfg, channel.PreparedOutboundMessage{
+			Target: s.target,
+			Message: channel.PreparedMessage{
+				Message: channel.Message{
+					Attachments: feishuLogicalAttachments(event.Attachments),
+				},
+				Attachments: event.Attachments,
+			},
 		})
 	case channel.StreamEventPhaseStart, channel.StreamEventPhaseEnd:
 		return nil
 	case channel.StreamEventAgentStart, channel.StreamEventAgentEnd, channel.StreamEventProcessingStarted, channel.StreamEventProcessingCompleted, channel.StreamEventProcessingFailed:
 		return nil
 	case channel.StreamEventFinal:
-		if event.Final == nil || event.Final.Message.IsEmpty() {
+		if event.Final == nil || event.Final.Message.Message.IsEmpty() {
 			return nil
 		}
 		msg := event.Final.Message
 		bufText := strings.TrimSpace(s.textBuffer.String())
 		finalText := bufText
 		if finalText == "" {
-			finalText = strings.TrimSpace(msg.PlainText())
+			finalText = strings.TrimSpace(msg.Message.PlainText())
 		}
 		if finalText != "" {
 			if err := s.ensureCard(ctx, feishuStreamThinkingText); err != nil {
@@ -121,12 +123,13 @@ func (s *feishuOutboundStream) Push(ctx context.Context, event channel.StreamEve
 		}
 		if len(msg.Attachments) > 0 {
 			media := msg
-			media.Format = ""
-			media.Text = ""
-			media.Parts = nil
-			media.Actions = nil
-			media.Reply = nil
-			return s.adapter.Send(ctx, s.cfg, channel.OutboundMessage{
+			media.Message.Format = ""
+			media.Message.Text = ""
+			media.Message.Parts = nil
+			media.Message.Actions = nil
+			media.Message.Reply = nil
+			media.Message.Attachments = feishuLogicalAttachments(media.Attachments)
+			return s.adapter.Send(ctx, s.cfg, channel.PreparedOutboundMessage{
 				Target:  s.target,
 				Message: media,
 			})
@@ -146,6 +149,17 @@ func (s *feishuOutboundStream) Push(ctx context.Context, event channel.StreamEve
 	}
 }
 
+func feishuLogicalAttachments(attachments []channel.PreparedAttachment) []channel.Attachment {
+	if len(attachments) == 0 {
+		return nil
+	}
+	logical := make([]channel.Attachment, 0, len(attachments))
+	for _, att := range attachments {
+		logical = append(logical, att.Logical)
+	}
+	return logical
+}
+
 func (s *feishuOutboundStream) Close(ctx context.Context) error {
 	if s == nil {
 		return nil