feat(crm): align shared attachment payloads

internal/handler/api/v1/contact_handler.go

@@ -832,6 +832,36 @@ func (h *ContactHandler) ContactableInboxes(c *gin.Context) {
 	c.JSON(http.StatusOK, gin.H{"payload": payload})
 }
 
+// ListAttachments returns a contact's shared files across all visible conversations.
+// GET /api/v1/accounts/:id/contacts/:contact_id/attachments
+// Reference: Chatwoot Api::V1::Accounts::Contacts::AttachmentsController#index
+func (h *ContactHandler) ListAttachments(c *gin.Context) {
+	accountID := parseAccountIDParam(c)
+	if accountID == 0 {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid account id"})
+		return
+	}
+
+	contactID, err := parseUintParam(c, "contact_id")
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid contact id"})
+		return
+	}
+
+	p := pagination.Parse(c)
+	attachments, total, svcErr := h.svc.ListAttachments(c.Request.Context(), accountID, contactID, p.Offset, p.PerPage)
+	if svcErr != nil {
+		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to list contact attachments"})
+		return
+	}
+
+	payload := make([]any, 0, len(attachments))
+	for i := range attachments {
+		payload = append(payload, serializeAttachmentWithConversation(c.Request.Context(), h.svc.DB(), &attachments[i]))
+	}
+	c.JSON(http.StatusOK, gin.H{"meta": gin.H{"total_count": total}, "payload": payload})
+}
+
 // DeleteCustomAttributes removes all custom attributes from a contact.
 // DELETE /api/v1/accounts/:id/contacts/:contact_id/custom_attributes
 // Reference: Chatwoot contacts#destroy_custom_attributes