fix(persistence): migrate all pkg/persistence imports to plugins/infra/database and plugins/infra/cache

- Replace db.DB(ctx) with database.DB(ctx) from plugins/infra/database
- Replace db.Redis/db.PrefixedKey/db.GetJSON/db.SetJSON with cachepkg.* from plugins/infra/cache
- Replace pkg/persistence/idgen with pkg/idgen (already exists)
- Replace pkg/persistence/batchwriter with pkg/batchwriter (already exists)
- Replace pkg/persistence/migrator with pkg/migrator (already exists)
- Replace pkg/persistence/logstore with plugins/domain/risk_control/logstore
- Delete defunct pkg/{persistence,cap,message_gateway,push,shared,task}
- Fix vet issues: db alias in domain_test.go, driver_asynq_worker.TaskHandler reference
- Update Makefile architecture guard
- Update docs and skill references
- Update go.mod: gorilla/sessions promotion to direct dependency

plugins/domain/upload/task/rebuild_stats_test.go

@@ -8,7 +8,7 @@ import (
 	"testing"
 	"time"
 
-	"github.com/Rain-kl/Wavelet/pkg/persistence"
+	database "github.com/Rain-kl/Wavelet/plugins/infra/database"
 	"github.com/Rain-kl/Wavelet/pkg/testhelper"
 	"github.com/Rain-kl/Wavelet/plugins/domain/upload/models"
 )
@@ -33,13 +33,13 @@ func TestRebuildUploadStatsHandler_Execute(t *testing.T) {
 		},
 	}
 	for i := range uploads {
-		if err := db.DB(ctx).Create(&uploads[i]).Error; err != nil {
+		if err := database.DB(ctx).Create(&uploads[i]).Error; err != nil {
 			t.Fatalf("seed upload failed: %v", err)
 		}
 	}
 
 	// Corrupt stats to ensure rebuild recalculates from uploads.
-	if err := db.DB(ctx).Create(&models.UploadStat{
+	if err := database.DB(ctx).Create(&models.UploadStat{
 		Dimension: models.UploadStatDimensionTotal,
 		StatKey:   "",
 		FileCount: 0,
@@ -58,7 +58,7 @@ func TestRebuildUploadStatsHandler_Execute(t *testing.T) {
 	}
 
 	var totalStat models.UploadStat
-	if err := db.DB(ctx).
+	if err := database.DB(ctx).
 		Where("dimension = ? AND stat_key = ?", models.UploadStatDimensionTotal, "").
 		First(&totalStat).Error; err != nil {
 		t.Fatalf("load total stat failed: %v", err)