fix(#240): accessibility, color consistency, and reviewedPct denominator

- TranscriptionColumn progress bar: add aria-hidden="true" (the block count
  text above already communicates the value to screen readers)
- TranscriptionColumn weekly pulse: text-ink → text-ink-2 (matches
  SegmentationColumn, same semantic element)
- ReadyColumn reviewedPct: align denominator to annotationCount so the
  displayed percentage matches the SQL threshold used to classify "ready"
- page.svelte.spec.ts: add missing segmentationDocs/transcriptionDocs/
  readyDocs/weeklyStats to emptyData fixture

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

frontend/src/routes/page.svelte.spec.ts

@@ -44,6 +44,10 @@ const emptyData = {
 	stats: null,
 	incompleteCount: 0,
 	initialValues: { senderName: '', receiverName: '' },
+	segmentationDocs: [],
+	transcriptionDocs: [],
+	readyDocs: [],
+	weeklyStats: null,
 	error: null
 };