fix: fcps index oob

for some reason this doesn't crash for me, but this feature is just riddled with potential places this could happen
relevant thread (p2sr) https://discord.com/channels/146404426746167296/1247646622217932924/1247646622217932924

src/Features/FCPS.cpp

@@ -106,7 +106,7 @@ CON_COMMAND(sar_fcps_anim_start, "sar_fcps_anim_start <id> - start animating the
 		idx += g_events.size();
 	}
 
-	if (idx < 0 || idx > (int)g_events.size()) {
+	if (idx < 0 || idx >= (int)g_events.size()) {
 		console->Print("No such FCPS event!\n");
 		return;
 	}