feat(nikki): track Infinity Nikki

Adds the game and its Game8 events page. One `SOURCES` entry against the
existing game8 parser, plus one date shape that page needs:
`parseLabelledStartEnd` reads a duration cell holding `Start: <date>` and
`End: <date>` split by a `<br>`, which a tag-stripping reader flattens
into one run of text.

Four of the seven events say `End: Permanent`. That is the source telling
us there is no deadline, so they publish with `endsAt: null` and
`endPrecision: "unknown"` rather than a plausible date. The labelled cell
is also structure end to end, so it never becomes a summary — stripping
the leading half would leave "End: Permanent" standing where a
description belongs.

Verified by re-extracting the page with a throwaway script independent of
the parser: 7 rows in, 7 events out, every date matching.

Note the source itself is stale — its "Current Events" table still lists
January-May 2025 and "Upcoming Events" says there are none. The adapter is
right; the page looks abandoned, and Nikki coverage worth relying on needs
a second source at a higher priority.

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

src/ingest/parsers/game8.ts

@@ -5,6 +5,7 @@ import {
 } from "../../shared/schema.ts";
 import {
   parseFullRange,
+  parseLabelledStartEnd,
   parseMonthDayRange,
   parseMonthDayYear,
   parseOpenRange,
@@ -313,6 +314,11 @@ function isRequirementOnly(text: string): boolean {
 
 /** Strip a leading label and date range, leaving any description behind it. */
 function proseAfterDates(cell: string): string | null {
+  // A fully labelled "Start: … End: …" cell is structure end to end. Stripping
+  // the leading half would leave "End: Permanent" standing where a description
+  // belongs — a date masquerading as a blurb.
+  if (parseLabelledStartEnd(cell) !== null) return null;
+
   const rest = cell
     .replace(/^\s*(period|duration|schedule|dates?)\s*[:：]\s*/i, "")
     .replace(RANGE_PREFIX, "")
@@ -330,6 +336,7 @@ function parseRange(
     parseFullRange(value) ??
     parseShortSlashRange(value) ??
     parseMonthDayRange(value) ??
+    parseLabelledStartEnd(value) ??
     parseOpenRange(value)
   );
 }