Step 2 (code quality): dedup + stop FE recomputing a server rule

- H1: tasksFromProfile takes the server's eligibleForHerregistratie decision
  instead of recomputing isHerregistratieEligible — the FE renders the rule,
  doesn't own it (ADR-0001). Policy reference impl kept for tests.
- M1: one shared runSubmit(fn, fallback) wrapper; the 4 submit-* commands keep
  only their payload mapping. +spec.
- M2: whenTag() kernel helper removes 10 repeated `as Extract<U,{tag}>` casts
  across the wizard/form components.

M4 (shared JA_NEE) folded into the upcoming i18n pass (clean dedup needs
$localize labels to sit in shared without breaking the English-shared-UI rule).
L1 already resolved by the restyle commit.

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

src/app/registratie/domain/tasks.spec.ts

@@ -12,21 +12,20 @@ const base: Registration = {
 };
 
 describe('tasksFromProfile', () => {
-  it('offers herregistratie when within the deadline window', () => {
-    const tasks = tasksFromProfile(base, new Date('2026-06-27'));
+  it('offers herregistratie when the server says eligible, with the formatted deadline', () => {
+    const tasks = tasksFromProfile(base, true);
     expect(tasks).toHaveLength(1);
     expect(tasks[0].to).toBe('/herregistratie');
     expect(tasks[0].description).toContain('31 december 2026');
   });
 
-  it('offers nothing when the deadline is far away', () => {
-    const far: Registration = { ...base, status: { tag: 'Geregistreerd', herregistratieDatum: '2030-12-31' } };
-    expect(tasksFromProfile(far, new Date('2026-06-27'))).toHaveLength(0);
+  it('offers nothing when the server says not eligible', () => {
+    expect(tasksFromProfile(base, false)).toHaveLength(0);
   });
 
-  it('surfaces a notice for a suspended registration', () => {
+  it('surfaces a notice for a suspended registration (independent of eligibility)', () => {
     const reg: Registration = { ...base, status: { tag: 'Geschorst', geschorstTot: '2027-01-01', reden: 'Onderzoek' } };
-    const tasks = tasksFromProfile(reg, new Date('2026-06-27'));
+    const tasks = tasksFromProfile(reg, false);
     expect(tasks).toHaveLength(1);
     expect(tasks[0].title).toContain('geschorst');
     expect(tasks[0].description).toBe('Onderzoek');
@@ -34,7 +33,7 @@ describe('tasksFromProfile', () => {
 
   it('surfaces a notice for a struck-off registration', () => {
     const reg: Registration = { ...base, status: { tag: 'Doorgehaald', doorgehaaldOp: '2025-01-01', reden: 'Op eigen verzoek' } };
-    const tasks = tasksFromProfile(reg, new Date('2026-06-27'));
+    const tasks = tasksFromProfile(reg, false);
     expect(tasks).toHaveLength(1);
     expect(tasks[0].title).toContain('doorgehaald');
   });

src/app/registratie/domain/tasks.ts

@@ -1,5 +1,5 @@
 import { Registration } from './registration';
-import { herregistratieDeadline, isHerregistratieEligible } from './registration.policy';
+import { herregistratieDeadline } from './registration.policy';
 
 /**
  * What the dashboard's "Wat moet ik regelen" list needs. Pure presentation data
@@ -17,15 +17,15 @@ function formatNL(d: Date): string {
 }
 
 /**
- * Derive the open tasks for a professional from their registration (pure;
- * `today` is injected so it's testable). Herregistratie within its window is the
- * primary action; a suspended/struck-off registration surfaces as a notice-task.
- * Reuses the same rules the detail/summary use (registration.policy).
+ * Derive the open tasks for a professional (pure). Eligibility is the server's
+ * decision (`decisions.eligibleForHerregistratie`), passed in — the FE renders it,
+ * it does not recompute the rule (ADR-0001). The deadline is still formatted
+ * client-side for the task copy (presentation, not a rule).
  */
-export function tasksFromProfile(reg: Registration, today: Date): PortalTask[] {
+export function tasksFromProfile(reg: Registration, eligibleForHerregistratie: boolean): PortalTask[] {
   const tasks: PortalTask[] = [];
 
-  if (isHerregistratieEligible(reg, today)) {
+  if (eligibleForHerregistratie) {
     const deadline = herregistratieDeadline(reg);
     tasks.push({
       title: 'Vraag uw herregistratie aan',