hub v0.90.1 — the digest's per-app lines stop repeating the filesystem figures (R-182)

Found by reading the first REAL digest, not by design. Every app row ended with
the same usage clause the mail already prints once on its own Filesystem line.
On a two-app box that is untidy; down a list of a dozen it is the same forty
characters twelve times, pushing the part that DIFFERS off a phone screen at
07:00 — the only moment this mail has to work.

The reserve's refusal message is authored for a single-app alert where naming
the filesystem is right, so the message is unchanged; the digest trims the
duplicate when rendering. trimRepeatedUsage removes ONLY an exact
"— <target path>:" suffix, so an unrelated reason is untouched and a reason that
is nothing but the usage clause is left alone rather than emptied.

Also updates TestRecoveryUnitCaptureFailed_NeverReachesTheCustomer, which
required the OPERATOR to be emailed a per-app capture failure. That was correct
when the event was the only signal and is wrong now that it is the record and
the digest is the notification. Its customer-safety claim is unchanged and is
why the test still exists; the operator assertion is inverted with the reasoning
written in place, and R-158's guarantee is shown to have MOVED, not weakened.

manifests/hub.yaml

@@ -125,7 +125,7 @@ spec:
     spec:
       containers:
         - name: hub
-          image: gitea.dooplex.hu/admin/felhom-hub:0.90.0
+          image: gitea.dooplex.hu/admin/felhom-hub:0.90.1
           ports:
             - containerPort: 8080
               name: http