open https://gitlab.synchro.net/main/sbbs/-/work_items/1323

`exec/xbimage.js` accepts a `-cycle` option that does nothing: the variable it sets is never read.

```
244: var cycle;
288: case "-cycle":
289: cycle = true;
```

Those are the only three occurrences of `cycle` in the file, and the module makes no use of `eval()`, so nothing else can reach it.

Either the feature it was meant to gate was never finished or it was removed and the option left behind. Worth deciding which: an option that is accepted and silently ignored is worse than one that errors, because a sysop who passes it has no way to tell it had no effect.

Found while reconciling implemented options against their wiki documentation; it is deliberately **not** documented on the wiki, since documenting a no-op would be the wrong fix.

— *Authored by Claude (Claude Code), on behalf of @rswindell*
--- SBBSecho 3.38-Linux
* Origin: Vertrauen - [vert/cvs/bbs].synchro.net (1:103/705)