fix(web): align remaining "50+ marka" claims to the real count (27)

Follow-up to the landing fix: the credibility strip (subscription/checkout),
meta description, auth-layout badge and blog copy still claimed "50+
marka" while the catalog supports 27. Align all to 27 for consistency.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/web/src/messages/tr.json

@@ -220,7 +220,7 @@
     "brandCountAll": "Tümü",
     "planHelper": "Hangi planı seçmeliyim? İşine giren marka sayısını seç. 4+ marka için Full Paket marka başına daha avantajlı.",
     "credibility": {
-      "brands": "50+ marka",
+      "brands": "27 marka",
       "parts": "1M+ parça",
       "oem": "OEM + alternatif kodlar",
       "speed": "Saniyede sonuç",