feat(phase2): bulk delete + audit log; update roadmap/parity docs

internal/audit/audit.go

@@ -0,0 +1,56 @@
+package audit
+
+import (
+	"context"
+	"database/sql"
+	"encoding/json"
+)
+
+// Action type constants.
+const (
+	ActionKick         = "KICK"
+	ActionBan          = "BAN"
+	ActionUnban        = "UNBAN"
+	ActionMute         = "MUTE"
+	ActionUnmute       = "UNMUTE"
+	ActionRoleCreate   = "ROLE_CREATE"
+	ActionRoleUpdate   = "ROLE_UPDATE"
+	ActionRoleDelete   = "ROLE_DELETE"
+	ActionMemberRoles  = "MEMBER_ROLES_UPDATE"
+	ActionChannelCreate = "CHANNEL_CREATE"
+	ActionChannelUpdate = "CHANNEL_UPDATE"
+	ActionChannelDelete = "CHANNEL_DELETE"
+	ActionServerUpdate  = "SERVER_UPDATE"
+	ActionMessageDelete = "MESSAGE_DELETE"
+	ActionBulkDelete    = "BULK_DELETE"
+)
+
+// Logger writes audit log entries to the database.
+type Logger struct {
+	db *sql.DB
+}
+
+// NewLogger creates a new audit logger.
+func NewLogger(db *sql.DB) *Logger {
+	return &Logger{db: db}
+}
+
+// Log records a single audit entry.
+func (l *Logger) Log(ctx context.Context, serverID, userID, actionType, targetType, targetID, reason string, changes map[string]interface{}) error {
+	if l == nil || l.db == nil {
+		return nil
+	}
+	var changesJSON []byte
+	var err error
+	if len(changes) > 0 {
+		changesJSON, err = json.Marshal(changes)
+		if err != nil {
+			return err
+		}
+	}
+	_, err = l.db.ExecContext(ctx, `
+		INSERT INTO audit_log (server_id, user_id, action_type, target_type, target_id, reason, changes)
+		VALUES ($1, $2, $3, $4, $5, $6, $7)
+	`, serverID, userID, actionType, targetType, targetID, reason, changesJSON)
+	return err
+}