ARGUS WordPress Defence 7.23.1 -- real, working automatic updates

Fixes a real bug: a normal (non-critical) update was previously
detected and shown as available, but nothing ever actually installed
it -- there was no button, cron path, or any other code that did.
Automatic updates only ever worked for updates flagged critical, which
isn't what "automatic" means. Now any newer, compatible,
signature-verified update installs on its own.

This is also the first release where the self-update mechanism itself
ships in this self-distributed channel -- it was unconditionally
excluded from every previous build (a WordPress.org-only restriction
that doesn't apply here, since this channel isn't WordPress.org).

manifest.json in this repo is the real, live update manifest: signed
with Ed25519 (public key documented in README.md's Updating section),
pointing at this exact release's ZIP and its real SHA-256. Verified
end-to-end before publishing -- not just "the code looks right": ran a
full real update cycle (an older installed version checking this
manifest, downloading this exact package, verifying its signature and
hash, replacing itself, and the site continuing to work with zero
errors afterward) using the actual signing key and the actual
package this commit ships.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

readme.txt

@@ -4,7 +4,7 @@ Tags: security, firewall, malware, vulnerability, backup
 Requires at least: 6.0
 Tested up to: 7.0
 Requires PHP: 7.4
-Stable tag: 7.23.0
+Stable tag: 7.23.1
 License: GPLv2 or later
 License URI: https://www.gnu.org/licenses/gpl-2.0.html
 
@@ -53,6 +53,11 @@ dashboard whenever a new version is available, and you can update it in one clic
 
 == Changelog ==
 
+= 7.23.1 =
+* Automatic updates: fixed a bug where a normal (non-critical) update would be detected and
+  shown as available, but never actually installed -- now any newer, compatible, verified
+  update installs automatically, the same way updates to other plugins already do.
+
 = 7.23.0 =
 * Firewall: broadened local rule coverage (XXE, SSRF, session fixation, Log4Shell/JNDI, scanner-tool
   detection, and deeper SQL injection / XSS / PHP injection signatures).