feat(server,cli): improve attachment support across issue and comment APIs

- Add --attachment flag to `multica issue create` CLI command
- Fix CreateComment response to include linked attachments instead of empty array
- Include attachments inline in GetIssue API response (matching Jira/ClickUp pattern)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

server/internal/handler/comment.go

@@ -148,7 +148,9 @@ func (h *Handler) CreateComment(w http.ResponseWriter, r *http.Request) {
 		h.linkAttachmentsByIDs(r.Context(), comment.ID, issue.ID, req.AttachmentIDs)
 	}
 
-	resp := commentToResponse(comment, nil, nil)
+	// Fetch linked attachments so the response includes them.
+	groupedAtt := h.groupAttachments(r, []pgtype.UUID{comment.ID})
+	resp := commentToResponse(comment, nil, groupedAtt[uuidToString(comment.ID)])
 	slog.Info("comment created", append(logger.RequestAttrs(r), "comment_id", uuidToString(comment.ID), "issue_id", issueID)...)
 	h.publish(protocol.EventCommentCreated, uuidToString(issue.WorkspaceID), authorType, authorID, map[string]any{
 		"comment":             resp,

server/internal/handler/issue.go

@@ -36,6 +36,7 @@ type IssueResponse struct {
 	CreatedAt          string                  `json:"created_at"`
 	UpdatedAt          string                  `json:"updated_at"`
 	Reactions          []IssueReactionResponse `json:"reactions,omitempty"`
+	Attachments        []AttachmentResponse    `json:"attachments,omitempty"`
 }
 
 type agentTriggerSnapshot struct {
@@ -142,6 +143,18 @@ func (h *Handler) GetIssue(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
+	// Fetch issue-level attachments.
+	attachments, err := h.Queries.ListAttachmentsByIssue(r.Context(), db.ListAttachmentsByIssueParams{
+		IssueID:     issue.ID,
+		WorkspaceID: issue.WorkspaceID,
+	})
+	if err == nil && len(attachments) > 0 {
+		resp.Attachments = make([]AttachmentResponse, len(attachments))
+		for i, a := range attachments {
+			resp.Attachments[i] = h.attachmentToResponse(a)
+		}
+	}
+
 	writeJSON(w, http.StatusOK, resp)
 }