Say every Administration refusal in the reader's language

Stalwart explains a refused change in English, and several of its words
reached the page as they were: "Invalid domain name" for a reserved TLD,
"Invalid email address" for a catch-all, a grant refusal, and ihasmail's own
proxy messages. Every registry error type now has its own message, and a
value one of the registry's string validators refused is recognised by the
validator's wording and explained again. A domain clash or a missing domain
is worded for a domain rather than an account.

The one exception is kept on purpose: a password policy's reason follows a
translated sentence, because the rule is the server's and dropping it would
leave no way to find out why.

The mock now refuses a reserved TLD and a catch-all without a domain the way
the live server did. KNOWN-ISSUES records the fix, and that the last two live
cases -- an administrator-set password and the outranking guard -- held.

15 new strings in all nine catalogues, 3 retired; strings falling back to
English stay at 16.

web/src/views/admin/DomainsAdmin.tsx

@@ -47,7 +47,7 @@ export function DomainsAdmin({ selectedId }: { selectedId?: string }) {
       } catch (err) {
         if (!cancelled) {
           setPage({ domains: [], total: 0 });
-          setError(describeDirectoryError(err));
+          setError(describeDirectoryError(err, "domain"));
         }
       }
     })();