A hosts file cannot express a wildcard, so '*.youtube.com' was only ever the
base domain plus the guessed labels. The patterns the server now hands over
as unexpandable are answered by a stub on 127.0.0.1, and the helper owns one
systemd-resolved drop-in that points just those zones at it:
* the stub is listening before the drop-in is written, and the drop-in is
removed before the stub stops, so a zone's queries never land on a dead
port;
* stub and route live as long as the app, not the interval: between
intervals they forward everything, instead of restarting resolved (and
dropping its cache) on every pomodoro;
* a crashed run leaves a world-readable drop-in the next start adopts, and
the stub comes back before anything else;
* masks with nothing routable after their last '*' ('*gram*') are reported
as unenforceable, not silently dropped.
The Blocker page now reports what is really in place — the hosts region, the
routed zones, and the masks this machine cannot do — rather than the whole
expansion. 39 desktop tests, including the ordering invariants.
