Pause a registry's WHOIS server after it refuses a query (closes #218)

The fetcher kept one interval for every registry, so a registry that
refused a query was asked again within seconds. RIPE blocked the test
host's address that way.

The WHOIS client now pauses an RIR's or NIC.br's server for an hour
after the server refuses a query. A refused or reset connection is a
refusal, and so is an %ERROR:201: or %ERROR:202: line. Lookups at the
other servers go on. A lookup whose RIR is paused leaves the AS stale,
and counts as neither a success nor a failure. IANA is never paused,
because a pause of IANA would stop every lookup. NIC.br's hour-long
skip after its over-limit answer is now the same pause.

Model: opus-5-5

TODO.md

@@ -35,6 +35,14 @@ tested.
 
 # Completed Steps
 
+- 2026-11-02: RouteWatch pauses an RIR's or NIC.br's WHOIS server for an hour
+  after the server refuses a query. A refused or reset connection is a refusal.
+  So is an answer with an `%ERROR:201:` or `%ERROR:202:` line. Lookups at the
+  other servers go on. An AS whose RIR is paused is looked up after the pause.
+  IANA is never paused, because a pause of IANA would stop every lookup. A
+  refusal by IANA is an ordinary failure. NIC.br is also paused for an hour
+  after it says RouteWatch has passed NIC.br's query limit. Before, the fetcher
+  asked a server again within seconds of a refusal (closes #218)
 - 2026-11-02: the AS handler never waits for a database write. Its batch holds
   one entry per AS, with the earliest and the latest time of its updates. So the
   batch no longer grows with the feed's rate. It used to hold one entry for each