Bug fixes: fast-nav substring yonu + nano timeout

Tum gpt-5.5 -> gpt-5-nano (matcher fiyat tasarrufu)

Realtime: gpt-realtime-2 -> gpt-realtime-mini (~%70 tasarruf)

Background refresh: 1 saat -> 24 saat

Trek XML feed: 3.5MB -> 1.2MB temiz feed (picture/price alanlari yok)

Mirror V2 content into V1 (snapshot for continued development)