feat(gameboot-windows): add game installers configuration with valorant and lol

Add installers.json configuration file with official installation sources for Valorant and League of Legends. This file specifies download URLs from Riot's CDN and installation parameters for the game installer script.

Note: URLs are region-specific (EU default) and may require periodic verification as Riot frequently updates these resources.

configs/releng/airootfs/usr/local/share/fws/gameboot-windows/installers.json

@@ -0,0 +1,17 @@
+{
+  "_comment": "Sources d'installation OFFICIELLES, telechargees au 1er boot par Install-Games.ps1. FWS ne redistribue AUCUN binaire de jeu : tout est telecharge depuis Riot. ATTENTION : Riot CHANGE regulierement ces URLs (region/patchline) -> a VERIFIER (bouton Telecharger sur playvalorant.com / leagueoflegends.com, copier le lien). Region par defaut : EU (utilisateur fr_CH). Mets 'autoinstall': false pour ne pas installer un jeu au 1er boot.",
+
+  "valorant": {
+    "autoinstall": true,
+    "url": "https://valorant.secure.dyn.riotcdn.net/channels/public/x/installer/current/live.live.eu.exe",
+    "installer": "valorant-setup.exe",
+    "silentargs": ""
+  },
+
+  "lol": {
+    "autoinstall": true,
+    "url": "https://lol.secure.dyn.riotcdn.net/channels/public/x/installer/current/live.euw.exe",
+    "installer": "lol-setup.exe",
+    "silentargs": ""
+  }
+}