feat(antigravity,gemini): add Gemini 3.8 Flash support and bump IDE fingerprint to 2.11.0

Co-authored-by: Schnee111 <daffamaarif.dev@gmail.com>
Co-authored-by: AhooraZen <ahoora935137@gmail.com>
Co-authored-by: anojndr <anojndr@gmail.com>
Co-authored-by: Emirhan <emirhan551952@gmail.com>

open-sse/providers/registry/gemini.js

@@ -36,6 +36,7 @@ export default {
     },
   },
   models: [
+    { id: "gemini-3.8-flash", name: "Gemini 3.8 Flash" },
     { id: "gemini-3.7-flash", name: "Gemini 3.7 Flash" },
     { id: "gemini-3.6-flash", name: "Gemini 3.6 Flash" },
     { id: "gemini-3.5-flash-lite", name: "Gemini 3.5 Flash Lite" },