HH-469: close WebSocket fanout contract gaps (#109)

* HH-469: close websocket fanout contract gaps

* fix: unify message sender contracts

---------

Co-authored-by: Rogee <rogee@ipao.vip>

backend/internal/model/attachment.go

@@ -1,5 +1,11 @@
 package model
 
+import (
+	"encoding/json"
+	"path/filepath"
+	"strings"
+)
+
 // Attachment represents a file attachment on a message.
 // Reference: Chatwoot Attachment model + P2B M3 spec
 type Attachment struct {
@@ -21,4 +27,29 @@ type Attachment struct {
 	Account Account `gorm:"foreignKey:AccountID" json:"account,omitempty"`
 }
 
-func (Attachment) TableName() string { return "attachments" }
+func (Attachment) TableName() string { return "attachments" }
+
+// PushEventData matches Chatwoot's attachment payload shared by HTTP and WebSocket messages.
+func (a *Attachment) PushEventData() map[string]any {
+	dataURL := a.FileURL
+	if dataURL == "" {
+		dataURL = a.ExternalURL
+	}
+	payload := map[string]any{
+		"id":         a.ID,
+		"message_id": a.MessageID,
+		"file_type":  a.FileType,
+		"account_id": a.AccountID,
+		"data_url":   dataURL,
+		"thumb_url":  a.ThumbURL,
+		"file_size":  a.FileSize,
+		"extension":  strings.TrimPrefix(filepath.Ext(a.FileName), "."),
+		"width":      a.Width,
+		"height":     a.Height,
+	}
+	metadata := map[string]any{}
+	if json.Unmarshal([]byte(a.Metadata), &metadata) == nil && len(metadata) > 0 {
+		payload["metadata"] = metadata
+	}
+	return payload
+}

backend/internal/model/captain_models.go

@@ -3,6 +3,8 @@ package model
 import (
 	"encoding/json"
 	"fmt"
+	"os"
+	"strings"
 
 	"github.com/pgvector/pgvector-go"
 )
@@ -89,6 +91,19 @@ type CaptainAssistant struct {
 
 func (CaptainAssistant) TableName() string { return "captain_assistants" }
 
+// PushEventData matches Chatwoot's public message-sender contract.
+func (a *CaptainAssistant) PushEventData() map[string]any {
+	avatarURL := strings.TrimRight(os.Getenv("FRONTEND_URL"), "/") + "/assets/images/dashboard/captain/logo.svg"
+	return map[string]any{
+		"id":          a.ID,
+		"name":        a.Name,
+		"avatar_url":  avatarURL,
+		"description": a.Description,
+		"created_at":  a.CreatedAt,
+		"type":        "captain_assistant",
+	}
+}
+
 // DefaultAssistantConfig returns the default configuration for a new Captain Assistant.
 // Reference: Chatwoot Captain::Assistant default config values
 func DefaultAssistantConfig() map[string]interface{} {

backend/internal/model/contact.go

@@ -34,6 +34,22 @@ type Contact struct {
 
 func (Contact) TableName() string { return "contacts" }
 
+// PushEventData matches Chatwoot's public message-sender contract.
+func (c *Contact) PushEventData() map[string]any {
+	return map[string]any{
+		"additional_attributes": jsonMap(c.AdditionalAttributes),
+		"custom_attributes":     jsonMap(c.CustomAttributes),
+		"email":                 c.Email,
+		"id":                    c.ID,
+		"identifier":            c.Identifier,
+		"name":                  c.Name,
+		"phone_number":          c.PhoneNumber,
+		"thumbnail":             c.AvatarURL,
+		"blocked":               c.Blocked,
+		"type":                  "contact",
+	}
+}
+
 // BeforeSave syncs location/country_code from additional_attributes and upgrades contact_type.
 // Reference: Chatwoot before_save :sync_contact_attributes → Contacts::SyncAttributes
 func (c *Contact) BeforeSave(tx *gorm.DB) error {

backend/internal/model/user.go

@@ -47,6 +47,27 @@ type User struct {
 
 func (User) TableName() string { return "users" }
 
+// PushEventData matches Chatwoot's public message-sender contract.
+func (u *User) PushEventData() map[string]any {
+	availableName := u.DisplayName
+	if availableName == "" {
+		availableName = u.Name
+	}
+	availabilityStatus := "offline"
+	if u.Available {
+		availabilityStatus = "online"
+	}
+	return map[string]any{
+		"id":                  u.ID,
+		"name":                u.Name,
+		"available_name":      availableName,
+		"avatar_url":          u.AvatarURL,
+		"type":                "user",
+		"availability_status": availabilityStatus,
+		"thumbnail":           u.AvatarURL,
+	}
+}
+
 // BeforeCreate mirrors Chatwoot's Pubsubable concern by assigning every user a cable token.
 func (u *User) BeforeCreate(tx *gorm.DB) error {
 	if u.PubsubToken == "" {