fix: recognize CNNIC and DENIC throttle replies

"Queried interval is too short." (CNNIC) and DENIC's "access control limit
reached" weren't recognized, so a throttled .cn or .de lookup failed as
"unparseable" instead of "rate_limited". .cn has no RDAP, so its WHOIS
throttling was always misreported. The texts are from known registry replies,
not captured in this session.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/whois/throttle.test.ts

@@ -8,6 +8,8 @@ describe("detectWhoisRefusal", () => {
     "You have exceeded the allowed number of queries.",
     "Too many requests",
     "<!DOCTYPE html><html><body>Service Unavailable</body></html>",
+    "Queried interval is too short.",
+    "% Error: 55000000002 Connection refused; access control limit reached.",
   ])("classifies %j as rate_limited", (text) => {
     expect(detectWhoisRefusal(text)).toBe("rate_limited");
   });

src/whois/throttle.ts

@@ -11,6 +11,8 @@ const THROTTLE_PATTERNS: RegExp[] = [
   /quota\s+exceeded/i,
   /exceeded\s+.{0,40}(quer|limit|request|connection)/i,
   /too\s+many\s+(quer|request|connection)/i,
+  /queried interval is too short/i, // CNNIC
+  /access control limit/i, // DENIC: "Connection refused; access control limit reached"
   /^\s*<(!doctype|html)\b/i,
 ];