feat: upgrade schedule with cross-location views, day/time filters, and clickable trainers

- Add "Все студии" tab merging all locations by weekday with location sub-headers
- Location tabs show hall name + address subtitle for clarity
- Add day multi-select and time-of-day preset filters (Утро/День/Вечер) behind collapsible "Когда" button
- Make trainer and type names clickable in day cards for inline filtering
- Add group view clustering classes by trainer+type+location
- Remove trainer dropdown from filter bar — filter by clicking names in schedule
- Add searchable icon picker and lucide-react icon rendering for classes admin/section

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/components/sections/Classes.tsx

@@ -1,7 +1,7 @@
 "use client";
 
 import Image from "next/image";
-import { Flame, Sparkles, Wind, Zap, Star, Monitor } from "lucide-react";
+import { icons } from "lucide-react";
 import { SectionHeading } from "@/components/ui/SectionHeading";
 import { Reveal } from "@/components/ui/Reveal";
 import { ShowcaseLayout } from "@/components/ui/ShowcaseLayout";
@@ -9,14 +9,15 @@ import { useShowcaseRotation } from "@/hooks/useShowcaseRotation";
 import type { ClassItem, SiteContent } from "@/types";
 import { UI_CONFIG } from "@/lib/config";
 
-const iconMap: Record<string, React.ReactNode> = {
-  flame: <Flame size={20} />,
-  sparkles: <Sparkles size={20} />,
-  wind: <Wind size={20} />,
-  zap: <Zap size={20} />,
-  star: <Star size={20} />,
-  monitor: <Monitor size={20} />,
-};
+// kebab "heart-pulse" → PascalCase "HeartPulse"
+function toPascal(kebab: string) {
+  return kebab.split("-").map((s) => s.charAt(0).toUpperCase() + s.slice(1)).join("");
+}
+
+function getIcon(key: string) {
+  const Icon = icons[toPascal(key) as keyof typeof icons];
+  return Icon ? <Icon size={20} /> : null;
+}
 
 interface ClassesProps {
   data: SiteContent["classes"];
@@ -60,7 +61,7 @@ export function Classes({ data: classes }: ClassesProps) {
                       {/* Icon + name overlay */}
                       <div className="absolute bottom-0 left-0 right-0 p-6">
                         <div className="mb-2 inline-flex h-9 w-9 items-center justify-center rounded-lg bg-gold/20 text-gold-light backdrop-blur-sm">
-                          {iconMap[item.icon]}
+                          {getIcon(item.icon)}
                         </div>
                         <h3 className="text-2xl font-bold text-white">
                           {item.name}
@@ -87,7 +88,7 @@ export function Classes({ data: classes }: ClassesProps) {
                         : "bg-neutral-200/50 text-neutral-500 dark:bg-white/[0.06] dark:text-neutral-400"
                     }`}
                   >
-                    {iconMap[item.icon]}
+                    {getIcon(item.icon)}
                   </div>
                   <div className="min-w-0">
                     <p