refactor(battle-node): remove ScriptedBotParticipant and dev-affordance wiring

Deletes the scripted opponent and every entry point that created a
BattleType.Scripted session (the ?scripted=1 query opt-in, the
SoloDefaultsToScripted toggle, the resolver short-circuit, the WS handler case,
the bridge validation arm). Real two-client PvP and the Bot matchmaking-timeout
fallback are untouched. ResolveAsync drops its scriptedOptIn parameter.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

SVSim.EmulatedEntrypoint/appsettings.Development.json

@@ -9,7 +9,6 @@
     "BypassSteamTicket": true
   },
   "BattleNode": {
-    "SoloDefaultsToScripted": false,
     "DiagnosticLogging": true
   }
 }