feat(person): formatLifeDateRange takes date + precision, delegates to formatDocumentDate

New formatLifeDate single-date helper carries no glyph so cards can wrap
* / † in aria-hidden spans. Missing precision falls back to YEAR.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

frontend/src/lib/person/personLifeDates.ts

@@ -1,20 +1,44 @@
+import { formatDocumentDate, type DatePrecision } from '$lib/shared/utils/documentDate';
+
 /**
- * Formats the life date range for a person.
- * Examples:
- *   * 1882 – † 1944  (both)
- *   * 1882            (birth only)
- *   † 1944            (death only)
- *   ""                (neither)
+ * Formats one life date (birth or death) at the precision the data claims,
+ * delegating all rendering to {@link formatDocumentDate}. Returns '' for a
+ * missing date. Carries no * / † glyph — components that need the glyphs wrap
+ * them in their own `aria-hidden` markup so screen readers only hear the date.
+ *
+ * A missing precision falls back to YEAR: pre-V76 rows only knew a year, and
+ * a bare year is the only safe rendering for a date without precision metadata.
  */
-export function formatLifeDateRange(birthYear?: number | null, deathYear?: number | null): string {
-	if (birthYear && deathYear) {
-		return `* ${birthYear} – † ${deathYear}`;
+export function formatLifeDate(
+	date: string | null | undefined,
+	precision: DatePrecision | null | undefined,
+	locale?: string
+): string {
+	if (!date) {
+		return '';
 	}
-	if (birthYear) {
-		return `* ${birthYear}`;
-	}
-	if (deathYear) {
-		return `† ${deathYear}`;
-	}
-	return '';
+	return formatDocumentDate(date, precision ?? 'YEAR', null, null, locale);
+}
+
+/**
+ * Formats the full life date range as plain text, e.g. for dropdown subtitles.
+ * Examples:
+ *   * 14. März 1901 – † 2. November 1944   (both, DAY precision)
+ *   * 1882                                  (birth only, YEAR precision)
+ *   † ca. 1944                              (death only, APPROX precision)
+ *   ""                                      (neither)
+ */
+export function formatLifeDateRange(
+	birthDate: string | null | undefined,
+	birthDatePrecision: DatePrecision | null | undefined,
+	deathDate: string | null | undefined,
+	deathDatePrecision: DatePrecision | null | undefined,
+	locale?: string
+): string {
+	const birth = birthDate ? `* ${formatLifeDate(birthDate, birthDatePrecision, locale)}` : null;
+	const death = deathDate ? `† ${formatLifeDate(deathDate, deathDatePrecision, locale)}` : null;
+	if (birth && death) {
+		return `${birth} – ${death}`;
+	}
+	return birth ?? death ?? '';
 }