fix(wizard): wizard remains in "not ready" state if a custom init() was provided #6339

## Problem
The wizard remained in a "not ready" state if a custom `init()` was
provided, requiring manual toggles in the test code.

## Solution
- Wrap the user’s init() with a small decorator that sets _ready = true.
- Remove the manual toggles in wizardTestUtils.ts, letting the wizard
handle readiness on its own.

Author: muaydin

packages/core/src/shared/wizards/wizard.ts

@@ -94,7 +94,7 @@ export class Wizard<TState extends Partial<Record<keyof TState, unknown>>> {
     private assertReady() {
         // Check for `false` explicity so that the base-class constructor can access `this._form`.
         // We want to guard against confusion when implementing a subclass, not this base-class.
-        if (this._ready === false && this.init) {
+        if (this._ready === false) {
             throw Error('run() (or init()) must be called immediately after creating the Wizard')
         }
     }
@@ -113,7 +113,7 @@ export class Wizard<TState extends Partial<Record<keyof TState, unknown>>> {
         return this._stepOffset[1] + this.stateController.totalSteps
     }
 
-    public get _form() {
+    protected get _form() {
         this.assertReady()
         return this.__form
     }
@@ -136,14 +136,22 @@ export class Wizard<TState extends Partial<Record<keyof TState, unknown>>> {
         this._estimator = estimator
     }
 
-    public constructor(private readonly options: WizardOptions<TState> = {}) {
+    public constructor(protected readonly options: WizardOptions<TState> = {}) {
         this.stateController = new StateMachineController(options.initState as TState)
         this.__form = options.initForm ?? new WizardForm()
         this._exitStep =
             options.exitPrompterProvider !== undefined ? this.createExitStep(options.exitPrompterProvider) : undefined
 
         // Subclass constructor logic should live in `init()`, if it exists.
         this._ready = !this.init
+
+        if (typeof this.init === 'function') {
+            const _init = this.init.bind(this)
+            this.init = () => {
+                this._ready = true
+                return _init()
+            }
+        }
     }
 
     /**
@@ -166,7 +174,6 @@ export class Wizard<TState extends Partial<Record<keyof TState, unknown>>> {
         if (!this._ready && this.init) {
             this._ready = true // Let init() use `this._form`.
             await this.init()
-            delete this.init
         }
 
         this.assignSteps()

packages/core/src/test/shared/wizards/wizardTestUtils.ts

@@ -65,9 +65,7 @@ function failIf(cond: boolean, message?: string): void {
 export async function createWizardTester<T extends Partial<T>>(wizard: Wizard<T> | WizardForm<T>): Promise<Tester<T>> {
     if (wizard instanceof Wizard && wizard.init) {
         // Ensure that init() was called. Needed because createWizardTester() does not call run().
-        ;(wizard as any)._ready = true
         await wizard.init()
-        delete wizard.init
     }
 
     const form = wizard instanceof Wizard ? wizard.boundForm : wizard