<?xml version="1.0" encoding="UTF-8"?>
<!--
  VittSphere ONE — ROOT SITEMAP INDEX
  Replaces the old hand-maintained /sitemap.xml (18 KB, last touched May 2026).

  WHY THIS IS NOW AN INDEX, NOT A URL LIST
  ─────────────────────────────────────────
  The old file listed every blog post and calculator by hand. Three problems
  killed it:

    1. It went stale the moment anything was published. It had 13 calculators
       when the site had 30, and ~50 posts when the site had 83.
    2. Worse, it listed blog posts as  /blog/post.php?cat=X&slug=Y  and
       categories as  /blog/category.php?cat=X . Those URLs 301-redirect to
       the clean /blog/X/Y/ form (see the canonical-301 block in post.php).
       Feeding Google ~45 redirecting URLs is actively harmful — they get
       filed under "Page with redirect" and the sitemap URL never indexes.
    3. Some entries were marked "to be deployed" and pointed at pages that
       did not exist.

  This index points at three CHILD sitemaps instead. Two of them are generated
  from live data, so they can never go stale:

    /blog/sitemap.xml        → blog/sitemap.php, generated from the .md files
    /calculators/sitemap.php → generated from $CALCULATORS in registry.php
    /pages-sitemap.xml       → static, 4 root pages that essentially never change

  ADDING CONTENT NO LONGER REQUIRES TOUCHING ANY SITEMAP.
  Publish a post or register a calculator and it appears automatically.

  NOTE ON THE CALCULATOR ENTRY
  ─────────────────────────────
  This points at sitemap.PHP, not sitemap.xml, deliberately. As of 16 Aug 2026
  /calculators/sitemap.xml was still serving a stale 15-calculator response
  while /calculators/sitemap.php served the current 30. Once you have confirmed
  /calculators/sitemap.xml returns all 30 (delete any physical sitemap.xml file
  sitting in /calculators/, and make sure that folder's .htaccess is in place),
  you can switch the line below to the .xml form. Until then .php is the safe one.
-->
<sitemapindex xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">

  <!-- Root pages: homepage, about, contact, ITR landing -->
  <sitemap>
    <loc>https://one.vittsphere.com/pages-sitemap.xml</loc>
    <lastmod>2026-08-16</lastmod>
  </sitemap>

  <!-- Blog: hub + 7 category pages + every published article (dynamic) -->
  <sitemap>
    <loc>https://one.vittsphere.com/blog/sitemap.xml</loc>
    <lastmod>2026-08-16</lastmod>
  </sitemap>

  <!-- Calculators: hub + every calculator with status 'live' (dynamic) -->
  <sitemap>
    <loc>https://one.vittsphere.com/calculators/sitemap.php</loc>
    <lastmod>2026-08-16</lastmod>
  </sitemap>

</sitemapindex>
