templates, handlers, CSS, JS: special cakes UI, HTMX nav, dashboard overhaul

Special cakes UI: overlay drawer, basket integration, catalogue tag
filter, form parsing, JS save/edit/remove.
HTMX navigation: MainContent component, nav links with hx-get,
handlers return partial on HX-Request.
Dashboard: metrics grid, CakeBreakdown, OrderRow with status select,
CakeCounts/OrderCounts, torty filter, tort badge, results-pane.
Collapsible sidebar: toggle button, localStorage, CSS transitions.
Location field: dropdown replaced with pill toggle.
Inline style cleanup: moved to CSS classes (tag-grid, grow, icon.sm,
header-actions, toggle-group, success-icon, etc.).
Dead CSS removal: pagination, status-chip, badge-pill, login-page.
Helpers: exported CakeTitle/OrderTitle, added tagNames, tagIDsComma,
orderItemsDesc, specialCakeDetail, removed unused helpers.

server/templates/confirmation.templ

@@ -8,7 +8,7 @@ templ Confirmation(title string, id int) {
 
 templ ConfirmationBody(id int) {
 	<section class="confirmation">
-		<span class="material-symbols-outlined" style="font-size:3rem;color:var(--success-text)">check_circle</span>
+		<span class="material-symbols-outlined success-icon">check_circle</span>
 		<h2>{ strconv.Itoa(id) } — zapisano</h2>
 		<a href="/orders" class="btn primary" style="margin-top:1rem">
 			<span class="material-symbols-outlined">arrow_back</span>