feat(fp): WP-08 — one store idiom + machine naming + TEA MDX

Rename change-request.machine.ts's bare State/Msg to ChangeRequestState/
ChangeRequestMsg (the last machine not context-prefixed), document the
createStore-is-the-idiom + naming convention in CLAUDE.md §3, and add the
Foundations/State Machines (TEA) curriculum page. The wizard pages already
wired createStore (confirmed by reading each and by git log) -- the WP's
"hand-wired signal(model)" premise was stale; recorded as a deviation.

src/app/registratie/domain/change-request.machine.spec.ts

@@ -1,9 +1,9 @@
 import { describe, it, expect } from 'vitest';
-import { State, reduce, initial } from './change-request.machine';
+import { ChangeRequestState, reduce, initial } from './change-request.machine';
 
 const editingWith = (
   draft: Partial<{ straat: string; postcode: string; woonplaats: string }>,
-): State => ({
+): ChangeRequestState => ({
   tag: 'Editing',
   draft: { straat: '', postcode: '', woonplaats: '', ...draft },
   errors: {},
@@ -13,13 +13,13 @@ describe('change-request reduce', () => {
   it('SetField updates the draft while editing', () => {
     const s = reduce(initial, { tag: 'SetField', key: 'straat', value: 'Lange Voorhout 9' });
     expect(s.tag).toBe('Editing');
-    expect((s as Extract<State, { tag: 'Editing' }>).draft.straat).toBe('Lange Voorhout 9');
+    expect((s as Extract<ChangeRequestState, { tag: 'Editing' }>).draft.straat).toBe('Lange Voorhout 9');
   });
 
   it('Submit with an invalid draft stays Editing and reports field errors', () => {
     const s = reduce(editingWith({ straat: '', postcode: 'nope' }), { tag: 'Submit' });
     expect(s.tag).toBe('Editing');
-    const errors = (s as Extract<State, { tag: 'Editing' }>).errors;
+    const errors = (s as Extract<ChangeRequestState, { tag: 'Editing' }>).errors;
     expect(errors.straat).toBeTruthy();
     expect(errors.postcode).toBeTruthy();
   });
@@ -29,7 +29,7 @@ describe('change-request reduce', () => {
       tag: 'Submit',
     });
     expect(s.tag).toBe('Submitting');
-    expect((s as Extract<State, { tag: 'Submitting' }>).data.postcode).toBe('2514 EA');
+    expect((s as Extract<ChangeRequestState, { tag: 'Submitting' }>).data.postcode).toBe('2514 EA');
   });
 
   it('confirms and fails only from Submitting; Retry re-submits a failure', () => {

src/app/registratie/domain/change-request.machine.ts

@@ -23,13 +23,13 @@ export type Errors = Partial<Record<keyof Draft, string>>;
  * Submitting/Submitted/Failed carry the parsed `Valid`. Illegal states (submitting
  * an invalid draft, a success screen with errors) are unrepresentable.
  */
-export type State =
+export type ChangeRequestState =
   | { tag: 'Editing'; draft: Draft; errors: Errors }
   | { tag: 'Submitting'; data: Valid }
   | { tag: 'Submitted'; data: Valid; referentie: string }
   | { tag: 'Failed'; data: Valid; error: string };
 
-export const initial: State = {
+export const initial: ChangeRequestState = {
   tag: 'Editing',
   draft: { straat: '', postcode: '', woonplaats: '' },
   errors: {},
@@ -51,16 +51,16 @@ function validate(draft: Draft): Result<Errors, Valid> {
   return { ok: false, error: errors };
 }
 
-export type Msg =
+export type ChangeRequestMsg =
   | { tag: 'SetField'; key: keyof Draft; value: string }
   | { tag: 'Submit' }
   | { tag: 'Retry' }
   | { tag: 'SubmitConfirmed'; referentie: string }
   | { tag: 'SubmitFailed'; error: string }
   | { tag: 'Reset' }
-  | { tag: 'Seed'; state: State }; // mount a specific state (stories/tests)
+  | { tag: 'Seed'; state: ChangeRequestState }; // mount a specific state (stories/tests)
 
-export function reduce(s: State, m: Msg): State {
+export function reduce(s: ChangeRequestState, m: ChangeRequestMsg): ChangeRequestState {
   switch (m.tag) {
     case 'SetField':
       return s.tag === 'Editing' ? { ...s, draft: { ...s.draft, [m.key]: m.value } } : s;

src/app/registratie/ui/change-request-form/change-request-form.component.ts

@@ -10,7 +10,7 @@ import {
 } from '@registratie/ui/address-fields/address-fields.component';
 import { createStore } from '@shared/application/store';
 import { whenTag } from '@shared/kernel/fp';
-import { State, Msg, initial, reduce } from '@registratie/domain/change-request.machine';
+import { ChangeRequestState, ChangeRequestMsg, initial, reduce } from '@registratie/domain/change-request.machine';
 import { createSubmitChangeRequest } from '@registratie/application/submit-change-request';
 
 /**
@@ -70,10 +70,10 @@ export class ChangeRequestFormComponent {
   // adapter); the UI holds only this bound command. Field initializer = injection
   // context, like createStore below.
   private submit = createSubmitChangeRequest();
-  private store = createStore<State, Msg>(initial, reduce);
+  private store = createStore<ChangeRequestState, ChangeRequestMsg>(initial, reduce);
 
   /** Optional seed so Storybook / tests can mount any state directly. */
-  seed = input<State>(initial);
+  seed = input<ChangeRequestState>(initial);
 
   readonly state = this.store.model;
   protected dispatch = this.store.dispatch;