fix(couchbase): return decode errors from ListUsers instead of log.Fatal

log.Fatal calls os.Exit(1), so one malformed row would crash the
whole server on an admin list call. Flagged independently by both
review passes on this PR since it now also covers decodeDocument
failures.

Author: lakhansamani

internal/storage/db/couchbase/user.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"log"
 	"strings"
 	"time"
 
@@ -102,11 +101,11 @@ func (p *provider) ListUsers(ctx context.Context, pagination *model.Pagination)
 	for queryResult.Next() {
 		var raw json.RawMessage
 		if err := queryResult.Row(&raw); err != nil {
-			log.Fatal(err)
+			return nil, nil, err
 		}
 		user := &schemas.User{}
 		if err := decodeDocument(raw, user); err != nil {
-			log.Fatal(err)
+			return nil, nil, err
 		}
 		users = append(users, user)
 	}