fix: parse configured dispatch delay strings

internal/store/tasks.go

@@ -8,6 +8,8 @@ import (
 	"errors"
 	"fmt"
 	"math/big"
+	"strconv"
+	"strings"
 	"time"
 
 	"github.com/jmoiron/sqlx"
@@ -457,6 +459,9 @@ func jsonInt(value any) (int, bool) {
 	case json.Number:
 		parsed, err := typed.Int64()
 		return int(parsed), err == nil
+	case string:
+		parsed, err := strconv.Atoi(strings.TrimSpace(typed))
+		return parsed, err == nil
 	default:
 		return 0, false
 	}

internal/store/tasks_test.go

@@ -2,6 +2,28 @@ package store
 
 import "testing"
 
+func TestJSONInt(t *testing.T) {
+	tests := []struct {
+		name  string
+		value any
+		want  int
+		ok    bool
+	}{
+		{name: "number", value: float64(900), want: 900, ok: true},
+		{name: "numeric string", value: "1200", want: 1200, ok: true},
+		{name: "trimmed numeric string", value: " 900 ", want: 900, ok: true},
+		{name: "invalid string", value: "15 minutes", ok: false},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			got, ok := jsonInt(test.value)
+			if got != test.want || ok != test.ok {
+				t.Fatalf("jsonInt(%v) = (%d, %v), want (%d, %v)", test.value, got, ok, test.want, test.ok)
+			}
+		})
+	}
+}
+
 func TestRandomDelaySeconds(t *testing.T) {
 	for index := 0; index < 100; index++ {
 		value := randomDelaySeconds(900, 1200)