Assert the page really lands under the Nolimit menu, and bump to 1.5.0

Kristian's menu screenshot showed four plugins under Nolimit and not this one,
after a build that moved the page there had already merged. Two separate
problems behind that.

The version never moved. The rename and the menu change went out still calling
themselves 1.4.6 — the same number as the copy already installed. So two
different builds carried one version, which is the one thing a version number
exists to prevent, and nothing offered the new one as an update. Now 1.5.0.

And the tests could not have caught it if the code HAD been wrong. The only
menu assertion was that this plugin claims the label through
wpmgr_menu_title — which passes while the plugin is absent from the menu
entirely. The label and the membership are different facts, and the screenshot
showed exactly that pair: the menu said Nolimit, this plugin was not in it.

Three assertions now. The parent exists after wpmgr_ensure_menu(), this
plugin's page is among the children of WPMGR_MENU_SLUG, and — separately — the
main file lists includes/shared-menu.php in its is_admin() branch.

That third one is there because the first two are a reduced repro and say so:
the admin menu is only built in an admin request, and these run under WP-CLI
where is_admin() is false and class-admin.php is never included, so the test
has to require the files by hand. A by-hand require would pass even if the
plugin never loaded them in a real request. That is the half a reduced repro
always omits, so it is asserted on its own rather than assumed.

Checked while here, from the security session's report: no human_time_diff
anywhere in this plugin, so the half-translated "4 timer ago" seam does not
exist here. Nothing to fix.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

README.txt

@@ -4,7 +4,7 @@ Tags: woocommerce, discount, email, shipping, coupon
 Requires at least: 5.8
 Tested up to: 7.1
 Requires PHP: 7.4
-Stable tag: 1.4.6
+Stable tag: 1.5.0
 WC requires at least: 6.0
 WC tested up to: 11.1.0
 License: GPLv2 or later