fix: remove smartraveller.gov.au feeds causing 503 errors (#982)

The AU Smartraveller RSS feeds have been consistently returning 503
from both Vercel edge and Railway relay. Remove all references from
security-advisories feeds, rss-proxy allowed domains, and relay allowlist.

api/rss-proxy.js

@@ -281,7 +281,6 @@ const ALLOWED_DOMAINS = [
   'cointelegraph.com',
   // Security advisories — government travel advisory feeds
   'travel.state.gov',
-  'www.smartraveller.gov.au',
   'www.safetravel.govt.nz',
   // US Embassy security alerts
   'th.usembassy.gov',

scripts/ais-relay.cjs

@@ -4353,8 +4353,6 @@ const server = http.createServer(async (req, res) => {
         'feeds.capi24.com',  // News24 redirect destination
         'islandtimes.org',
         'www.atlanticcouncil.org',
-        'smartraveller.gov.au',
-        'www.smartraveller.gov.au',
       ];
       const parsed = new URL(feedUrl);
       // Block deprecated/stale feed domains — stale clients still request these

src/services/security-advisories.ts

@@ -63,27 +63,6 @@ const ADVISORY_FEEDS: AdvisoryFeed[] = [
     url: 'https://travel.state.gov/_res/rss/TAsTWs.xml',
     parseLevel: parseUsLevel,
   },
-  // Australia (DFAT Smartraveller) — all destinations
-  {
-    name: 'AU Smartraveller',
-    sourceCountry: 'AU',
-    url: 'https://www.smartraveller.gov.au/countries/documents/index.rss',
-    parseLevel: parseAuLevel,
-  },
-  // Australia — Do Not Travel specifically
-  {
-    name: 'AU DNT',
-    sourceCountry: 'AU',
-    url: 'https://www.smartraveller.gov.au/countries/documents/do-not-travel.rss',
-    parseLevel: () => 'do-not-travel',
-  },
-  // Australia — Reconsider
-  {
-    name: 'AU Reconsider',
-    sourceCountry: 'AU',
-    url: 'https://www.smartraveller.gov.au/countries/documents/reconsider-your-need-to-travel.rss',
-    parseLevel: () => 'reconsider',
-  },
   // New Zealand MFAT
   {
     name: 'NZ MFAT',