refactor(public): unify site copy with the About page voice

The About page addresses the reader formally and speaks as "we"; the
landing pages used informal second-person singular ("تعریف می‌کنی") and
the home hero was a slogan. Both now match the About tone.

Landing copy: all informal verb forms and possessives converted to the
formal plural. Home: hero headline and lead rewritten as a plain
statement of what we built, plus small wording passes on the devices,
specialties and stats blocks.

The home-page smoke assertion follows the new headline.

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

tests/Shared/LandingPageTest.php

@@ -68,7 +68,7 @@ class LandingPageTest extends WebTestCase
         $html = $this->html('/');
 
         self::assertSame(200, $this->client->getResponse()->getStatusCode());
-        self::assertStringContainsString('هوشمند، سریع و', $html);
+        self::assertStringContainsString('کارِ مطب،', $html);
     }
 
     public function testExistingRoutesAreNotShadowed(): void