fix(bulk-edit): cycle-2 blockers — restore initial-* props, missing import, scope Esc, edit-mode topbar

Felix B1 (data-loss regression on /documents/[id]/edit) — DocumentEditLayout
still passes initialDateIso, initialLocation, initialDocumentLocation, but
my cycle-1 cleanup removed those props. Result: existing values rendered
empty and a save would have overwritten them with "". Restored the props
on WhoWhenSection and DescriptionSection; initialisation now lives in
onMount so it runs exactly once and never stomps a parent-driven update on
a later prop change.

Felix B2 — `DescriptionSection.svelte:36` still had the top-level
`currentTitle = untrack(() => initialTitle)` mutation that I cleaned up in
WhoWhenSection but missed here. Same onMount-once treatment.

Leonie B5 — `enrich/+page.svelte:105` referenced `<BulkSelectionBar>` but
the import was lost in a prettier pass; svelte-check errored out and the
bar never rendered, leaving an 8 rem dead zone from the pb-32 reservation.
One-line fix: add the import.

Leonie B6 — Esc handler in `BulkSelectionBar` was unscoped and stole
Escape from NotificationBell, ConfirmDialog, HelpPopover, etc. (e.g.
selecting docs → opening notification bell → Esc would close the bell
AND silently wipe the selection). Now bails when an open dialog,
expanded menu, or popover is detected.

Elicit C1 — `BulkDocumentEditLayout` topbar now branches on `mode`:
shows "Massenbearbeitung" + "{count} werden bearbeitet" in edit mode
instead of the upload-flavoured "Mehrere Dokumente hochladen" + "werden
erstellt" copy. New i18n keys `bulk_edit_topbar_title` and
`bulk_edit_count_pill` in DE/EN/ES.

Tests added:
 - DocumentControllerTest.patchBulk_stripsCarriageReturnsAndNewlinesFromErrorMessages
   (Sara C2 follow-up — pin sanitizeForLog as a regression test)
 - BulkSelectionBar.spec — count=1 → "1 Dokument", count=2 → "2 Dokumente"
   (Sara C6 follow-up — pin the new bulk_edit_n_selected_one/_other branch)

Refs #225, PR #331

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/lib/components/document/BulkDocumentEditLayout.svelte

@@ -324,12 +324,20 @@ async function retrySave() {
 		</a>
 		<span class="text-ink-3" aria-hidden="true">·</span>
 		<span class="font-serif text-sm font-bold text-ink">
-			{isMulti ? m.bulk_title_multi() : m.bulk_title_single()}
+			{#if mode === 'edit'}
+				{m.bulk_edit_topbar_title()}
+			{:else}
+				{isMulti ? m.bulk_title_multi() : m.bulk_title_single()}
+			{/if}
 		</span>
 		{#if isMulti}
 			<span class="ml-auto flex items-center gap-3">
 				<span class="rounded-[2px] bg-accent px-2 py-0.5 text-xs font-bold text-primary">
-					{m.bulk_count_pill({ count: files.size })}
+					{#if mode === 'edit'}
+						{m.bulk_edit_count_pill({ count: files.size })}
+					{:else}
+						{m.bulk_count_pill({ count: files.size })}
+					{/if}
 				</span>
 				<button
 					type="button"