E2E: initiator (BRP/KvK) specs need seeded register-set fixtures to run on CI

[rubenvdlinde]

The brp-kvk-initiator e2e specs assert against personas and companies that only exist in a live personen-mock / KvK test environment:

• Stephan Janssen with BSN 999990627 and birthdate 1975-04-06
• Test EMZ Dagobert at KvK 69599084

tests/e2e/ci-seed.sh provisions the procest register + schemas but creates no brp/kvk register-set objects, so on a GitHub runner the initiator picker has nothing to find. Four of the six tests are therefore test.fixme with this issue referenced; the two that only exercise the picker shell (initiator type choice + the skippable path) stay live.

To re-enable: extend ci-seed.sh to POST the two fixture objects into the brp/kvk register sets (or point the register sets at a mock served from the runner), then drop the test.fixme markers.

Found while turning the shared E2E Tests (Playwright) job on in #709.

[rubenvdlinde]

Additional finding while fixing the E2E job: the StartCaseWidget is not wired into the Dashboard, so the initiator flow has no entry point at all.

src/manifest.json's Dashboard page declares twelve widgets — kpi-open-cases, kpi-overdue, kpi-completed, kpi-my-tasks (stat), cases-by-status, cases-by-type (chart), and open-cases, overdue-cases, my-tasks, deadline-alerts, task-reminders, stalled-cases (object-table). StartCaseWidget.vue exists in src/views/widgets/ but is referenced by none of them, so .start-case-widget__card never renders.

That means all six initiator tests are blocked, not just the four that need BRP/KvK fixtures — the two shell-only ones cannot click their way into the flow either. All six are now test.fixme.

So re-enabling needs two things:

1. Add the start-case widget to the Dashboard manifest (or point the specs at whatever the real entry point is now).
2. Seed the brp/kvk register-set fixtures described above.