Add branching intake wizard (derived steps + radio-group atom)

A second wizard demonstrating a BRANCHING flow: the visible steps are derived
from the answers by a pure `visibleSteps` function rather than stored, so
answering "buiten Nederland gewerkt? -> ja" or reporting few hours adds steps
and the progress denominator changes live. Same Elm-style store + RemoteData
patterns as the fixed wizard; answers persist to localStorage.

- intake.machine.ts: IntakeState union + Answers + visibleSteps + pure reduce (+spec)
- intake-wizard organism, intake.page, submit-intake command
- new radio-group atom (ControlValueAccessor) in shared/ui
- /intake route + dashboard link + concepts showcase section
- tighten Aantekening.type to a 'Specialisme' | 'Aantekening' union
- README + ARCHITECTURE updated

Verified live end-to-end (branches add steps 4->5->6, review, submit) with no
console errors; build, unit tests, and Storybook all green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/app/herregistratie/application/submit-intake.ts

@@ -0,0 +1,14 @@
+import { Result, ok, err } from '@shared/kernel/fp';
+import { ValidIntake } from '../domain/intake.machine';
+
+/**
+ * Command: send the intake questionnaire to the backend. Returns a Result so the
+ * caller branches on success/failure without try/catch. ponytail: faked with a
+ * timer; swap for a real POST when there's an API. The "uren must be > 0" rule
+ * lets the demo show the failure path.
+ */
+export async function submitIntake(data: ValidIntake): Promise<Result<string, void>> {
+  await new Promise((r) => setTimeout(r, 800));
+  if (data.uren === 0) return err('Aanvraag afgewezen: geen gewerkte uren geregistreerd.');
+  return ok(undefined);
+}