iidx: turn off camera access by default (#428)

## Link to GitHub Issue, if one exists
For #345 
Similar idea as https://github.com/spice2x/spice2x.github.io/pull/350

## Description of change
Disable camera access by default by setting `CONNECT_CAMERA` environment
var to 0 before launching. This was one of those "required" things
people clicked on, but now it's done automatically to reduce friction
for new users.

On cab setups (i.e., running without -iidx module), cameras will remain
on, unless user overrides it.

On franken setups (partial I/O) - user will need to specify what they
want via the new option, we can't guess correctly.

## Testing

src/spice2x/launcher/options.cpp

@@ -456,13 +456,30 @@ static const std::vector<OptionDefinition> OPTION_DEFINITIONS = {
         .category = "Game Options (Advanced)",
     },
     {
-        .title = "IIDX Disable Cameras",
+        // IIDXDisableCameras
+        .title = "IIDX Disable Cameras (DEPRECATED - no longer needed)",
         .name = "iidxdisablecams",
         .desc = "Disables cameras",
         .type = OptionType::Bool,
+        .hidden = true,
         .game_name = "Beatmania IIDX",
         .category = "Game Options",
     },
+    {
+        // IIDXCabCamAccess
+        .title = "IIDX Use Official AC Cams",
+        .name = "iidxcabcams",
+        .desc = "For IIDX25+, allow direct access to cameras from real arcade cabinets. "
+            "Only turn this on if you have OFFICIAL arcade cameras connected to the correct USB ports. Default: auto",
+        .type = OptionType::Enum,
+        .game_name = "Beatmania IIDX",
+        .category = "Game Options (Advanced)",
+        .elements = {
+            {"auto", ""},
+            {"off", ""},
+            {"on", ""}
+        },
+    },
     {
         // IIDXCamHook
         .title = "IIDX Cam Hook",