feat: add Girls' Frontline 2, from IOP Wiki

The best date material this project has after wiki.gg: every row states an
exact instant on both boundaries and names the zone, so nothing is converted
and nothing is assumed. `parseIsoClockRangeUtc` requires that `(UTC)` rather
than defaulting to it — a row that ever loses it should drop out instead of
landing hours off a boundary the reader is watching in-game.

The hazard here is the Server column. CN, EN and JP rows share one table and
the Chinese schedule runs about a year ahead, which is the akwiki CN-column
problem verbatim: publish EN, skip the rest. Betas are fenced off separately,
being dated exactly like everything else and playable by nobody, and the page
is an archive back to 2023, so currency is decided against ctx.now as in
bawiki. That leaves one live event today — thin, and true.

No resetOffsets: the EN boundaries land on three different clocks, which is a
patch window rather than a reset hour.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>

src/ingest/dates.ts

@@ -479,3 +479,40 @@ export function parseSlashClockZone(input: string): ParsedInstant | null {
   );
   return value === null ? null : { iso: value, precision: "exact" };
 }
+
+/**
+ * "2025-01-16 17:00 - 2025-02-06 02:59 (UTC)" → both instants, exact precision.
+ *
+ * IOP Wiki's GFL2 event tables put the whole period in one cell and — unusually
+ * for a community wiki — state the zone on every one of them. That makes this
+ * the only range reader here that converts nothing: the source has already done
+ * it, so both boundaries are exact and no offset is assumed anywhere.
+ *
+ * **The zone is required**, for the reason `parseSlashClockZone` requires its
+ * own: a cell that states a wall clock and no zone is a missing fact, not an
+ * invitation to read it as UTC. All 145 rows on the page carry `(UTC)` today,
+ * so the day one loses it that row should drop out rather than land hours off
+ * on a boundary the reader is standing in the game watching.
+ *
+ * Anchored at the start so a range cannot be found inside prose or a slug; left
+ * open at the end because the cell also carries an ICS export widget, whose
+ * markup the caller strips but whose container survives as trailing whitespace.
+ */
+export function parseIsoClockRangeUtc(
+  input: string,
+): { start: ParsedInstant; end: ParsedInstant } | null {
+  const re =
+    /^\s*(\d{4})-(\d{2})-(\d{2})\s+(\d{1,2}):(\d{2})\s*[-–—]\s*(\d{4})-(\d{2})-(\d{2})\s+(\d{1,2}):(\d{2})\s*\(UTC\)/i;
+  const m = re.exec(input);
+  if (!m) return null;
+
+  const n = (i: number) => Number(m[i]);
+  const startIso = iso(n(1), n(2), n(3), n(4), n(5));
+  const endIso = iso(n(6), n(7), n(8), n(9), n(10));
+  if (startIso === null || endIso === null) return null;
+
+  return {
+    start: { iso: startIso, precision: "exact" },
+    end: { iso: endIso, precision: "exact" },
+  };
+}