Bump wiki to 8c63db5 — the CB-539/CB-542 docs
Pairs with 244fbd9. The docs half lived on the submodule's own remote, so the
pointer bump is separate by necessity, not by preference.
The substantive part is not the new 'Run a worker on the subscription' entry but
the correction beside it: 'Give workers a toolchain' asserted flatly that an env:
entry cannot repoint a worker past the SubscriptionGuard. CB-539 made that false,
and the wiki went on claiming it until CB-542 closed the hole. The entry now
states the rule and its one exception together.
This commit is contained in: