feat: add landing page templates and registration modal

- Implemented header and hero section in _header.html.twig and _hero_art.html.twig.
- Created a pre-registration modal in _reg_modal.html.twig with form fields and validation.
- Added page scripts for dynamic behavior and interaction in _page_scripts.html.twig.
- Developed landing page structure in landing.html.twig, integrating header, footer, and modal.
- Introduced tests for landing page rendering and registry validation in LandingPageTest.php and LandingRegistryTest.php.

templates/public/_header.html.twig

@@ -0,0 +1,27 @@
+		<!-- ===================== Header ===================== -->
+		<header class="site-header" id="header">
+			<div class="wrap nav">
+				<a class="brand" href="#hero" aria-label="کلینیک پرو">
+					<b>کلینیک پرو</b>
+					<span class="dot"></span>
+					<small>مدیریت مطب</small>
+				</a>
+
+				<nav class="nav-links" id="navLinks">
+					<a href="#hero" class="active">خانه</a>
+					<a href="#features">امکانات</a>
+					<a href="#why">چرا کلینیک پرو</a>
+					<a href="#download" style="display:none">دانلود</a>
+					<a href="#contact">تماس با ما</a>
+					<a href="#" id="openRegModalNav" class="nav-reg-mobile">ثبت نام</a>
+				</nav>
+
+				<div class="nav-right">
+					<button class="nav-burger nav-toggle" id="navToggle" aria-label="منو">
+						<svg viewbox="0 0 24 24" fill="none"><path d="M4 7h16M4 12h16M4 17h16" stroke="currentColor" stroke-width="2.2" stroke-linecap="round"/></svg>
+					</button>
+					<button class="btn btn-ghost" id="openRegModal" style="font-size:13px;padding:8px 20px">ثبت نام</button>
+					<a href="/admin" class="btn btn-blue" style="font-size:13px;padding:8px 20px;text-decoration:none">ورود به پنل</a>
+				</div>
+			</div>
+		</header>