feat(epic2): Implement core authentication and authorization services

- Implement Audit Service (2.5)
  - gRPC server with Record and Query operations
  - Database persistence with audit schema
  - Service registry integration
  - Entry point: cmd/audit-service

- Implement Identity Service (2.2)
  - User CRUD operations
  - Password hashing with argon2id
  - Email verification and password reset flows
  - Entry point: cmd/identity-service
  - Fix package naming conflicts in user_service.go

- Implement Auth Service (2.1)
  - JWT token generation and validation
  - Login, RefreshToken, ValidateToken, Logout RPCs
  - Integration with Identity Service
  - Entry point: cmd/auth-service
  - Note: RefreshToken entity needs Ent generation

- Implement Authz Service (2.3, 2.4)
  - Permission checking and authorization
  - User roles and permissions retrieval
  - RBAC-based authorization
  - Entry point: cmd/authz-service

- Implement gRPC clients for all services
  - Auth, Identity, Authz, and Audit clients
  - Service discovery integration
  - Full gRPC communication

- Add service configurations to config/default.yaml
- Create SUMMARY.md with implementation details and testing instructions
- Fix compilation errors in Identity Service (password package conflicts)
- All services build successfully and tests pass

ent/enttest/enttest.go

@@ -0,0 +1,84 @@
+// Code generated by ent, DO NOT EDIT.
+
+package enttest
+
+import (
+	"context"
+
+	"git.dcentral.systems/toolz/goplt/ent"
+	// required by schema hooks.
+	_ "git.dcentral.systems/toolz/goplt/ent/runtime"
+
+	"entgo.io/ent/dialect/sql/schema"
+	"git.dcentral.systems/toolz/goplt/ent/migrate"
+)
+
+type (
+	// TestingT is the interface that is shared between
+	// testing.T and testing.B and used by enttest.
+	TestingT interface {
+		FailNow()
+		Error(...any)
+	}
+
+	// Option configures client creation.
+	Option func(*options)
+
+	options struct {
+		opts        []ent.Option
+		migrateOpts []schema.MigrateOption
+	}
+)
+
+// WithOptions forwards options to client creation.
+func WithOptions(opts ...ent.Option) Option {
+	return func(o *options) {
+		o.opts = append(o.opts, opts...)
+	}
+}
+
+// WithMigrateOptions forwards options to auto migration.
+func WithMigrateOptions(opts ...schema.MigrateOption) Option {
+	return func(o *options) {
+		o.migrateOpts = append(o.migrateOpts, opts...)
+	}
+}
+
+func newOptions(opts []Option) *options {
+	o := &options{}
+	for _, opt := range opts {
+		opt(o)
+	}
+	return o
+}
+
+// Open calls ent.Open and auto-run migration.
+func Open(t TestingT, driverName, dataSourceName string, opts ...Option) *ent.Client {
+	o := newOptions(opts)
+	c, err := ent.Open(driverName, dataSourceName, o.opts...)
+	if err != nil {
+		t.Error(err)
+		t.FailNow()
+	}
+	migrateSchema(t, c, o)
+	return c
+}
+
+// NewClient calls ent.NewClient and auto-run migration.
+func NewClient(t TestingT, opts ...Option) *ent.Client {
+	o := newOptions(opts)
+	c := ent.NewClient(o.opts...)
+	migrateSchema(t, c, o)
+	return c
+}
+func migrateSchema(t TestingT, c *ent.Client, o *options) {
+	tables, err := schema.CopyTables(migrate.Tables)
+	if err != nil {
+		t.Error(err)
+		t.FailNow()
+	}
+	if err := migrate.Create(context.Background(), c.Schema, tables, o.migrateOpts...); err != nil {
+		t.Error(err)
+		t.FailNow()
+	}
+}