fix: the wizards' seed input never arrived (RD-39)

All three wizard containers read `this.seed()` in the constructor. Angular
binds component inputs after the constructor runs, so the value was always the
`initial` default, `seeded !== initial` was always false, and every mount took
the `draftSync.resume()` branch. The `seed` input was dead code.

The two single-step forms built on the same idiom read the input inside the
microtask and work correctly. That contrast is the diagnosis.

Impact: 21 seeded wizard stories rendered step 1 instead of the state they
asked for. Storybook is this repo's UI test surface, so the states with no
other coverage were exactly the ones not rendering — Submitting, Submitted,
Failed, Ingediend, Mislukt. The a11y runner checks that whatever rendered is
accessible, never that the right thing rendered, so nothing caught it.
Production was unaffected: no route binds `seed`.

Read the input inside the microtask, matching the two forms. Turn the spec's
old `componentInstance.dispatch(...)` workaround into a real regression test
through `componentRef.setInput('seed', ...)`.

Verified: with the intake fix reverted the two spec cases fail; with it, 319
pass. `npm run ci --full` is green, and the newly rendered markup produced no
axe violations. A browser check of seven seeded stories across all three
wizards asserts text only reachable from a seed.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

libs/shared/docs/behaviour-spec.mdx

@@ -20,7 +20,7 @@ tested where._
 
 Every bullet below is a real test name from the suite — an `it()` title (frontend) or a test
 method name (backend), read as a sentence. Nothing here is hand-written prose: this page
-**is** the suite, reshaped for a business reader. 562 frontend behaviours across
+**is** the suite, reshaped for a business reader. 563 frontend behaviours across
 9 contexts; 261 backend behaviours across 42 test
 classes.
 
@@ -383,6 +383,7 @@ classes.
 
 #### IntakeWizardComponent
 
+- honours the seed input
 - renders each field group as its own grey <fieldset>
 
 #### STEPS (fixed) and inline questions