docs(tmdb): label the folding stand-ins as illustrative, not as history

Review caught that the substitution left synthetic titles inside sentences
that assert observed fact: the architecture doc claimed a particular folded
query "returns zero results while `Лейка` returns the show" and named the
stand-ins as the titles that were searched, missed and negatively cached, and
several comments read the same way. The titles never existed, so the reading
is wrong in the one direction that matters — a future reader debugging a
regression would take them for production evidence.

Keep the claim that is actually established, which is a class-level one:
under the old single-form design every Cyrillic title carrying "й"/"ё" and
every Arabic title carrying a hamza form was searched folded, missed, and
cached as missing for the negative TTL. Present the strings themselves as
illustrative stand-ins chosen to fold the same way. The verified invariant —
what NFD does to those letters, and what the two tiers therefore produce — is
unchanged and still assertable, because it is a property of the text rather
than of any title.

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

libs/shared/database/src/lib/connection.ts

@@ -976,9 +976,9 @@ function widenTmdbMetadataMediaTypeCheck(sqliteDb: Database.Database): void {
  * - unversioned → v2: title normalization learned to strip appended
  *   language/quality tags.
  * - v2 → v3: the search query stopped being the folded comparison key. Under
- *   v2 every title with a Cyrillic "й"/"ё" was searched folded ("леика" for
- *   "Лейка", "ежик" for "Ёжик"), got no answer, and was cached as missing for
- *   7 days.
+ *   v2 every title with a Cyrillic "й"/"ё" was searched folded — the fold
+ *   spells them "и" and "е", as in the illustrative "леика" for "Лейка" —
+ *   got no answer, and was cached as missing for 7 days.
  * - v3 → v4: year evidence became tiered. Under v3 a series admitted only by
  *   the "premiered earlier" tolerance competed with an exact-year match on
  *   popularity alone, so a new series resolved to its older, better-known