Internet exposure checks and response rate limiting

Jarl works out which views are reachable from the internet (match-clients
ending in a catch-all, not private-looking addresses: an internal view of a
global IPv6 prefix is still yours; a server without views: open allow-query
and a non-private listen address), with a per-view override (schema 9), and
checks public ones: rate limiting, open resolver, minimal-any, cache
snooping, open NOTIFY and transfers, version and host name, management
interfaces. Fixes are staged like any change, including rate limiting from
ISC's example in log-only mode with the secondaries exempt, then enforcing.
named logs what rate limiting limits (or would, in log-only mode, where its
counters don't move) as query-errors; Jarl routes those lines to its log
and counts them (rrl breakdown, ratelimited top lists, Prometheus
jarl_ratelimit_logged_total), shown on the new Exposure page.

A change that newly opens a public view up must be confirmed (accept_risk,
--accept-risk, a checkbox on the Changes page; 409 confirm_risk
otherwise). Findings can be acknowledged with a reason and stay visible as
info. GET /exposure, POST /exposure/fix|ack|unack, jarl exposure,
docs/exposure.md.

Also fixes query statistics skipping TSIG-signed queries ("IP#port/key
NAME" in named's log).

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

internal/web/static/assets/pages/dashboard.js

@@ -2,7 +2,7 @@ import { h, mount, time, fmtTime, relTime, problemsList, badge, plural } from ".
 import { get, state } from "../api.js";
 
 export async function render(el) {
-  const [st, mine] = await Promise.all([get("/status"), get("/changesets", { status: "open", mine: 1, limit: 50 }).catch(() => [])]);
+  const [st, mine, exposure] = await Promise.all([get("/status"), get("/changesets", { status: "open", mine: 1, limit: 50 }).catch(() => []), get("/exposure").catch(() => null)]);
   const s = st.engine || {};
   // The user's own changesets with something in them: what the Changes page shows.
   const pending = mine.filter((c) => (c.ops || []).length).length;
@@ -16,6 +16,7 @@ export async function render(el) {
     card("Access", plural((s.counts || {}).acls || 0, "ACL"), plural((s.counts || {}).tsig_keys || 0, "TSIG key")),
     card("Options", (s.counts || {}).options ?? "–", "server, view, zone and top-level"),
     st.backup ? backupCard(st.backup) : null,
+    exposure ? exposureCard(exposure) : null,
   );
   const last = s.last_applied;
   const parts = [h("div", { class: "page-head" },
@@ -106,6 +107,16 @@ function backupCard(b) {
   return card("Backup", value, sub);
 }
 
+// exposureCard sums up the internet exposure page.
+function exposureCard(r) {
+  const pub = r.scopes.filter((s) => s.public);
+  let warn = r.server.filter((f) => f.severity === "warning").length;
+  for (const s of r.scopes) warn += s.findings.filter((f) => f.severity === "warning").length;
+  const value = !pub.length ? badge("nothing public", "ok") : warn ? badge(plural(warn, "warning"), "warn") : badge("hardened", "ok");
+  const sub = pub.length ? "public: " + pub.map((s) => s.view || "the server").join(", ") : "no view is reachable from the internet";
+  return h("a", { class: "card link", href: "#/exposure" }, h("div", { class: "label" }, "Exposure"), h("div", { class: "value" }, value), h("div", { class: "sub" }, sub));
+}
+
 function card(label, value, sub) {
   return h("div", { class: "card" }, h("div", { class: "label" }, label), h("div", { class: "value" }, value), sub ? h("div", { class: "sub" }, sub) : null);
 }