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/infra/storage/objectstore/config.go

@@ -12,7 +12,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/Rain-kl/Wavelet/pkg/persistence"
+	database "github.com/Rain-kl/Wavelet/plugins/infra/database"
 
 	"gorm.io/gorm"
 )
@@ -110,7 +110,7 @@ func LoadConfig(ctx context.Context) (Config, error) {
 
 func loadConfigByKey(ctx context.Context, key string, fallback Config) (Config, error) {
 	var val string
-	err := db.DB(ctx).Table("w_system_configs").Where("key = ?", key).Pluck("value", &val).Error
+	err := database.DB(ctx).Table("w_system_configs").Where("key = ?", key).Pluck("value", &val).Error
 	if err != nil {
 		if errors.Is(err, gorm.ErrRecordNotFound) {
 			return fallback, nil
@@ -182,7 +182,7 @@ func SaveActiveConfig(ctx context.Context, cfg Config) error {
 }
 
 func saveSystemConfig(ctx context.Context, key string, value any, description string) error {
-	err := db.DB(ctx).Transaction(func(tx *gorm.DB) error {
+	err := database.DB(ctx).Transaction(func(tx *gorm.DB) error {
 		return upsertSystemConfig(ctx, tx, key, value, description)
 	})
 	if err == nil && key == "storage_config" {