fix(sidebar): render the flow sidebar once, not twice

[rubenvdlinde]

E2E went red on development:

1) [chromium] › tests/e2e/ci/flow-controls.spec.ts:181:5
   Error: the flow sidebar did not render — the controls are unreachable again
   Error: strict mode violation: locator('.cn-flow-sidebar') resolved to 2 elements

This deletes a workaround, not a fix

#3103 fixed the real problem. CnAppRoot only offered the manifest's sidebarComponent as the default content of its #sidebar slot, and this app fills that slot — so by Vue's ordinary slot mechanic the consumer won and the manifest key was live config that rendered nothing. #3103 passes the component through as a slot prop so App.vue can render it.

What it did not do is remove the workaround that existed because the manifest key rendered nothing: a hardcoded <FlowDetailSidebar> in SideBars.vue, whose own comment says exactly that —

"These are declared on the manifest page as sidebarComponent: FlowDetailSidebar … It could never render here, though … The manifest key was live config that rendered nothing."

With the manifest route working, both rendered. The E2E caught it precisely as it should.

So the workaround goes, and the comment left in its place records that the manifest is now the single source of truth — because adding a route back here for a page that declares sidebarComponent will duplicate it again.

The unused import and components entry go with it: a registration left behind after its template use is removed is the next reader's puzzle.

src/App.vue is Prettier-formatted here too — the same one-file fix is in #3107, and whichever lands first makes the other a no-op.

Verification

eslint            exit 0
webpack build     compiled (warnings only, no errors)
npm run format    exit 0

[github-actions]

Quality Report — ConductionNL/openregister @ 8e86bb0

Check	PHP	Vue	Security	License	Tests
lint	✅
phpcs	✅
phpmd	✅
psalm	✅
phpstan	✅
phpmetrics	✅
eslint		✅
stylelint		✅
build		✅
check-specs		✅
test-l10n		✅
test-l10n-parity		✅
format		✅
check-schema-l10n		✅
check-l10n-js		✅
composer			✅	✅ 174/174
npm			✅	✅ 547/547
app:check-code	⏭️
info.xml	✅
REUSE	❌
PHPUnit					✅
Newman					✅
Playwright					🚨 NO VERDICT — enabled but never ran
Hydra gates					✅

---

Quality workflow — 2026-08-30 13:19 UTC

Download the full PDF report from the workflow artifacts.