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

go.mod

@@ -19,6 +19,7 @@ require (
 	github.com/go-jose/go-jose/v4 v4.1.4
 	github.com/google/go-cmp v0.7.0
 	github.com/google/uuid v1.6.0
+	github.com/gorilla/sessions v1.4.0
 	github.com/gorilla/websocket v1.5.3
 	github.com/hibiken/asynq v0.26.0
 	github.com/maypok86/otter/v2 v2.3.0
@@ -118,7 +119,6 @@ require (
 	github.com/google/btree v1.0.0 // indirect
 	github.com/gorilla/context v1.1.2 // indirect
 	github.com/gorilla/securecookie v1.1.2 // indirect
-	github.com/gorilla/sessions v1.4.0 // indirect
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.29.0 // indirect
 	github.com/hashicorp/go-version v1.9.0 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect