Confirm changes automatically from the client that made them

A change made over the network answers with a one-time confirm_token
and closes its connection (HTTP/2: a GOAWAY). The web UI and hc send the
token straight back to /confirm, which accepts it only for the newest
change, from the same user and API token, the same address, and over a
new connection: proof that the client can still reach the API through
the new ruleset (an established connection would get through anyway). A
change that cuts its client off can't be confirmed so, and rolls back by
itself. The setting manual_confirm (hc settings set --auto-confirm off)
and hc --no-confirm leave confirming to a person. Changes through the
local socket still need no confirmation. e2e: 136 checks, among them a
lockout change rolled back without anyone confirming.

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

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

@@ -1,7 +1,7 @@
 // Import: an existing nftables ruleset as Housecarl's configuration.
 import { h, mount, field, textarea, input, checkbox, errorBox, copyBox } from "../ui.js";
 import { api } from "../api.js";
-import { refreshProbation } from "../app.js";
+import { refreshProbation, autoConfirm } from "../app.js";
 
 export async function render(el) {
   const json = textarea("", { rows: 6, class: "mono", placeholder: "the output of: sudo nft -j list ruleset" });
@@ -21,12 +21,13 @@ export async function render(el) {
       mount(out, h("div", { class: "msg " + (dry ? "info" : "ok") },
         dry ? "Would import: " : "Imported: ",
         `${st.zones.length} zones, ${st.sets.length} sets, ${st.services.length} services, ${st.rules.length} rules, ${st.forwards.length} port forwards, ${st.snats.length} source NAT rules, ${st.redirects.length} redirects.`,
-        r.confirm_by ? " It is on probation: confirm it in the banner." : ""),
+        r.confirm_by && !r.confirm_token ? " It is on probation: confirm it in the banner." : ""),
       r.notes.length ? h("div", { class: "panel" }, h("h2", null, "Notes"), h("ul", null, r.notes.map((n) => h("li", null, n)))) : null,
       r.raw.length ? h("div", { class: "panel" }, h("h2", null, "Kept as raw rules"), h("ul", { class: "mono small" }, r.raw.map((n) => h("li", null, n)))) : null,
       !dry ? h("p", null, "Check the ", h("a", { href: "#/rules" }, "rules"), " and ", h("a", { href: "#/nat" }, "NAT"),
         "; both rulesets apply until the old table goes: ", copyBox("sudo hc takeover \"inet main\"")) : null);
-      if (!dry) refreshProbation();
+      if (!dry && r.confirm_token) autoConfirm(r.confirm_token);
+      else if (!dry) refreshProbation();
     } catch (e) { mount(out, errorBox(e)); }
   };
   mount(el,