fix(document-detail): force edit panel on notification deep-link

Comments only render inside TranscriptionEditView, so a deep-link
into a document with existing reviewed transcriptions landed the
user in read mode with no comment element in the DOM — the scroll
target silently missed.

scrollToCommentFromQuery now takes a setPanelMode callback and calls
it with 'edit' whenever both query params are present. The page's
own transcribe-mode $effect checks a skipInitialPanelMode flag the
deep-link flow sets, so its default-panel-mode logic doesn't race
against the explicit override.

Two new helper tests pin the contract: panel mode is forced to
'edit' both when transcribe mode is off (entering fresh) and when
it is already on (same-page notification click).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

frontend/src/lib/utils/deepLinkScroll.ts

@@ -1,6 +1,7 @@
 export type DeepLinkScrollOptions = {
 	transcribeMode: boolean;
 	setTranscribeMode: (value: boolean) => void;
+	setPanelMode: (mode: 'read' | 'edit') => void;
 	loadBlocks: () => Promise<void>;
 	setActiveAnnotationId: (id: string) => void;
 	flashAnnotation: (annotationId: string) => void;
@@ -25,6 +26,11 @@ export async function scrollToCommentFromQuery(
 		await opts.loadBlocks();
 	}
 
+	// Comments only render in edit mode — force it so the deep-link target
+	// exists in the DOM even if the document already has reviewed transcriptions
+	// (which default the panel to read mode).
+	opts.setPanelMode('edit');
+
 	opts.setActiveAnnotationId(annotationId);
 	await opts.afterTick();