Docs for RFC6962 Logs EOL (#2099)

This updates the documentation on our ct-logs page to note the EOL of
our RFC6962 logs (and woodpecker along with it). I think we can include
more information here in the future, but this ensures we are at least
up-to-date with the state of the world.

Leave data/transparency.json in place for reference, though it's not
currently used.

Author: mcpherrinm

content/en/docs/ct-logs.html

@@ -1,7 +1,7 @@
 ---
 title: Certificate Transparency (CT) Logs
 slug: ct-logs
-lastmod: 2025-08-27
+lastmod: 2025-12-11
 show_lastmod: 1
 ---
 
@@ -40,84 +40,46 @@ <h2>Funding</h2>
   <a href="https://www.abetterinternet.org/sponsor/">sponsoring or donating</a>.
 </p>
 
-<h2>Architecture</h2>
-
-<p>
-  Check out our blog to see
-  <a href="https://letsencrypt.org/2019/11/20/how-le-runs-ct-logs.html"
-    >How Let's Encrypt Runs CT Logs</a
-  >!
-</p>
-
-<h2>Log Monitoring</h2>
-
-<p>
-  Let's Encrypt has created an open-source CT log monitoring tool called
-  <a href="https://github.com/letsencrypt/ct-woodpecker">CT Woodpecker</a>. We
-  use this tool to monitor the stability and compliance of our own logs, and we
-  hope others will find it to be useful as well.
-</p>
-
 <h2>CT Logs</h2>
 <p>
 Information about the various lifecycle states that a CT log progresses through can be found <a href="https://googlechrome.github.io/CertificateTransparency/log_states.html">here</a>.
 </p>
 
 <h3>Sunlight</h3>
 <p>
-  Let's Encrypt is transitioning to operating logs based on <a href="https://sunlight.dev">Sunlight</a>.
+  Let's Encrypt currently operates <a href="https://c2sp.org/static-ct-api">static-ct</a> logs based on
+  <a href="https://sunlight.dev">Sunlight</a>.
+</p>
+<p>
   Information including accepted roots, public keys, log IDs, and shard intervals are available at each log's
   landing page, linked below.
 </p>
-<p>Sycamore and Willow are our new production CT logs, accepting certificates from trusted CAs.</p>
+<p>Sycamore and Willow are our production CT logs, accepting certificates from trusted CAs.</p>
 <ul>
   <li><b>Sycamore</b>: <a href="https://log.sycamore.ct.letsencrypt.org/">log.sycamore.ct.letsencrypt.org</a></li>
   <li><b>Willow</b>: <a href="https://log.willow.ct.letsencrypt.org/">log.willow.ct.letsencrypt.org</a></li>
 </ul>
-<p>Twig is a test log, accepting certificates from trusted CAs as well as some additional test CAs, including the Let's
-  Encrypt staging environment.</p>
+<p>
+  Twig is a test log, accepting certificates from trusted CAs as well as some additional test CAs, including the Let's
+  Encrypt staging environment.
+</p>
 <ul>
   <li><b>Twig</b>: <a href="https://log.twig.ct.letsencrypt.org/">log.twig.ct.letsencrypt.org</a></li>
 </ul>
 
 
-{{< ct_logs data="production" >}}
-<li>
-  Oak is incorporated into the
-  <a href="https://support.apple.com/en-us/HT209255">Apple</a> and
-  <a href="https://github.com/chromium/ct-policy/blob/master/ct_policy.md"
-    >Google</a
-  >
-  CT programs.
-</li>
-<li>Our production ACME API environment submits certificates here.</li>
-{{< /ct_logs >}} {{< ct_logs data="testing" >}}
-<li>
-  SCTs from these logs <b>SHOULD NOT</b> be incorporated into publicly trusted
-  certificates.
-</li>
-<li>
-  The Let's Encrypt production and
-  <a href="/docs/staging-environment">staging</a> ACME API environments both
-  submit certificates to Sapling, but the production environment does not use
-  the resulting SCTs.
-</li>
-<li>
-  We test new versions of
-  <a href="http://github.com/google/trillian">Trillian</a> and
-  <a href="https://github.com/google/certificate-transparency-go"
-    >certificate-transparency-go</a
-  >
-  here before deploying them to production.
-</li>
-<li>
-  Sapling's accepted roots list includes all of the Oak accepted roots, plus
-  additional test roots.
-</li>
-<li>
-  Sapling can be used by other certificate authorities for testing purposes.
-</li>
-{{< /ct_logs >}}
+<h3>RFC 6962 Logs EOL</h3>
+<p>
+  Let's Encrypt formerly ran a log based on Trillian, implementing the RFC 6962 API. It is currently available
+  read-only, and will be shut down in February 2026. For more information, see the
+  <a href="https://letsencrypt.org/2025/08/14/rfc-6962-logs-eol">
+    end of life plan for our RFC 6962 Certificate Transparency logs
+  </a>. URLs and log keys can be found in Google and Apple's CT log lists, if required.
+  The old production log was called Oak.
+</p>
+<p>
+  We also ran test logs called Testflume and Sapling, which are no longer available.
+</p>
 
 <h2>Log Operations</h2>
 <p>