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.

CLAUDE.md

@@ -75,7 +75,14 @@ model a discriminated union instead.** Three tools, all in `shared/application`:
 - **Elm-style store** (`store.ts` → `createStore(initial, reduce)`) — all state in
   one Model; change only by `dispatch(msg)` → **pure** `reduce(model, msg)`. Models
   are tagged unions (see `herregistratie.machine.ts`, `intake.machine.ts`). Templates
-  send messages, never mutate.
+  send messages, never mutate. **`createStore` is the one wiring idiom** — a page
+  never hand-rolls `signal(model)` + a local `dispatch()`. Naming: a top-level
+  machine's State/Msg types are context-prefixed (`ChangeRequestState`,
+  `ChangeRequestMsg`), never bare `State`/`Msg`; a top-level machine exports
+  `initial` + `reduce`. A **composable sub-machine** embedded inside a parent
+  model keeps prefixed *value* exports instead (`initialUpload`/`reduceUpload`,
+  see `upload.machine.ts`) — prefixing there avoids alias noise at the
+  composition site.
 - **`Result<E,T>` + value objects** ("parse, don't validate") — raw input becomes a
   branded type only via a parser returning `Result` (`registratie/domain/value-objects/`:
   `Postcode`, `Uren`, `BigNummer`). Once you hold the type, never re-check it.