Search toggle icon on mobile, 2-col desktop; update README badges

Search position:
- Desktop: 2 columns (16.667%), menu fills the rest
- Mobile: collapses to a magnifying glass icon button (like the
  hamburger) that expands the search form via Bootstrap collapse

README:
- Version moved to badge (03.09.04)
- Joomla badge updated to 5.x | 6.x
- PHP badge updated to 8.1+
- Removed inline VERSION from title

Remove obsolete build-release.sh and minify.js scripts (replaced
by CI workflow and PHP helper).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/index.php

@@ -448,7 +448,10 @@ $wa->useScript('user.js');         // js/user.js
 				</nav>
 			<?php endif; ?>
 			<?php if ($this->countModules('search', true)) : ?>
-				<div class="container-search">
+				<button class="search-toggler d-lg-none" type="button" data-bs-toggle="collapse" data-bs-target="#headerSearchCollapse" aria-controls="headerSearchCollapse" aria-expanded="false" aria-label="<?php echo Text::_('JSEARCH_FILTER_SUBMIT'); ?>">
+					<span class="fa-solid fa-magnifying-glass" aria-hidden="true"></span>
+				</button>
+				<div class="container-search collapse d-lg-block" id="headerSearchCollapse">
 					<jdoc:include type="modules" name="search" style="none" />
 				</div>
 			<?php endif; ?>

src/media/css/template.css

@@ -14477,13 +14477,20 @@ li.current a {
 	min-width: 12rem;
 }
 
-.container-header .navbar-toggler {
+.container-header .navbar-toggler,
+.container-header .search-toggler {
 	color: var(--mainmenu-nav-link-color, #fff);
 	border-color: var(--mainmenu-nav-link-color, #fff);
 	font-size: 1.25rem;
 	cursor: pointer;
 }
 
+.container-header .search-toggler {
+	background: none;
+	border: none;
+	padding: 0.25rem 0.5rem;
+}
+
 .container-header .container-search {
 	margin-top: 0.75em;
 }
@@ -18665,6 +18672,10 @@ nav[data-toggle=toc] .nav-link.active+ul{
 		margin-top: 0.5rem;
 	}
 
+	.container-header .container-search.collapse:not(.show) {
+		display: none;
+	}
+
 	.mod-finder__search.input-group {
 		max-width: 100%;
 	}
@@ -18683,8 +18694,8 @@ nav[data-toggle=toc] .nav-link.active+ul{
 	}
 
 	.container-header .container-search {
-		flex: 0 0 25%;
-		max-width: 25%;
+		flex: 0 0 16.667%;
+		max-width: 16.667%;
 		margin-top: 0;
 	}
 }