feat(site): publish /australia.html — managed Odoo hosting in Australia (Sydney)

New flat landing page for Australian buyers, built from the approved Phase 2
copy with the five buyer-lens changes (R1-R5) applied. English only, no hreflang.

- australia.html: hero, five sections, four-plan pricing table (On the Rise
  heroed), 7-question FAQ, final CTA band; house CI (midnight/brass/cream,
  Marcellus + Inter), page-scoped CSS only.
- Buy CTAs are native POST forms to the live checkout with Australia (Sydney)
  pre-selected (basket product_id 4, verified against the homepage card).
- images/city-sydney.webp: city-sydney.jpg resized 6720x2240 -> 1920x640,
  9.8 MB -> 131 KB.
- index.html: the Sydney server card now links to the new page.
- sitemap.xml + llms.txt: page registered.

Evidence: verify-html.py PROBLEMS 0, verify-australia-page.py PROBLEMS 0,
JSON-LD parses, impeccable detect run (findings recorded).

index.html

@@ -288,7 +288,7 @@
           <div class="server-card"><div class="server-city">Manchester</div><div class="server-region">United Kingdom</div></div>
           <div class="server-card"><div class="server-city">Mumbai</div><div class="server-region">India</div></div>
           <div class="server-card"><div class="server-city">S&atilde;o Paulo</div><div class="server-region">Brazil</div></div>
-          <div class="server-card"><div class="server-city">Sydney</div><div class="server-region">Australia</div></div>
+          <div class="server-card"><a class="server-city" href="australia.html" title="Managed Odoo hosting in Australia — Sydney">Sydney</a><div class="server-region">Australia</div></div>
         </div>
       </div>
     </section>