feat(drivers): implement in-process cron scheduler driver plugin

backend/plugins/drivers/driver_inproc_cron/plugin_test.go

@@ -0,0 +1,49 @@
+// Copyright 2026 Arctel.net
+// SPDX-License-Identifier: Apache-2.0
+
+package driver_inproc_cron_test
+
+import (
+	"context"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"Wavelet/core"
+	"Wavelet/plugins/drivers/driver_inproc_cron"
+	"Wavelet/plugins/drivers/driver_inproc_worker"
+)
+
+func TestInprocCronPlugin(t *testing.T) {
+	ctx := core.NewContext(context.Background())
+
+	workerPlugin := driver_inproc_worker.New()
+	require.NoError(t, workerPlugin.Apply(ctx))
+	require.NoError(t, workerPlugin.Start(context.Background()))
+	defer func() { _ = workerPlugin.Stop(context.Background()) }()
+
+	cronPlugin := driver_inproc_cron.New()
+	assert.Equal(t, "driver_inproc_cron", cronPlugin.Name())
+	assert.Equal(t, core.DriverTypeScheduler, cronPlugin.Type())
+	require.NoError(t, cronPlugin.Apply(ctx))
+
+	var cronTriggered atomic.Int32
+	ctx.Tasks().Register("cron:heartbeat", func(ctx context.Context) error {
+		cronTriggered.Add(1)
+		return nil
+	})
+
+	// Every second cron spec
+	ctx.Schedules().RegisterCron("* * * * * *", "cron:heartbeat", nil)
+
+	require.NoError(t, cronPlugin.Start(context.Background()))
+
+	require.Eventually(t, func() bool {
+		return cronTriggered.Load() >= 1
+	}, 3*time.Second, 100*time.Millisecond)
+
+	require.NoError(t, cronPlugin.Stop(context.Background()))
+}