feat(seo): add eight landing pages for the clusters we had nothing for

Keyword research put the head demand on four phrases — clinic management
software, doctor's office software, online booking, and the price/comparison
questions that precede a purchase — and we only had a page for one of them.
The new pages cover the head terms (clinic management, online booking), the
buying intent (price, how to choose, download), the positioning that separates
a hosted product from the installed ones that dominate these results (web
based, no install), and two long-tails where competition is thin (clinic
accounting, psychology practice).

The download page deliberately answers the intent rather than the wording:
someone searching for an installer wants to try something without paying, and
the page gives them that while explaining why there is nothing to install.

Copy is written per page rather than templated — eight pages saying the same
thing in different words is duplicate content, and every claim on them maps to
something the product actually does. Internal links from the older pages were
repointed at the new head-term pages, and the registry tests no longer hardcode
the page count: they now assert that every declared slug has a page, and that
titles, headings and descriptions stay unique.

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

tests/Shared/LandingPageTest.php

@@ -84,7 +84,9 @@ class LandingPageTest extends WebTestCase
         $xml = $this->html('/sitemap.xml');
         $doc = new \SimpleXMLElement($xml);
 
-        self::assertCount(8, $doc->url, 'sitemap باید خانه و هفت لندینگ را داشته باشد');
+        // خانه + هر صفحهٔ فرود. عدد از خودِ رجیستری می‌آید تا افزودن خوشهٔ کلیدواژهٔ
+        // تازه این تست را نشکند، ولی جاافتادن یک صفحه از sitemap هنوز قرمز شود.
+        self::assertCount(1 + count($this->registry->all()), $doc->url);
 
         foreach (array_keys($this->registry->all()) as $slug) {
             self::assertStringContainsString(rawurlencode($slug), $xml, "«{$slug}» در sitemap نیست");