Align catalog with Bambu Lab product line, add conditional filters and admin sidebar

- Add master catalog (bambuLabCatalog.ts) as single source of truth for materials, finishes, colors, and refill/spool availability
- Fix incorrect finish-per-material mappings (remove PLA: 85A/90A/95A HF/FR/GF/HF, add ASA: Basic/CF/Aero, fix PETG/PC)
- Implement cascading filters on public site: material restricts finish, finish restricts color
- Add AdminSidebar component across all admin pages
- Redirect /upadaj to /dashboard when already authenticated
- Update color hex mappings and tests to match official Bambu Lab names

app/upadaj/sales/page.tsx

@@ -4,6 +4,7 @@ import { useState, useEffect, useCallback, useRef } from 'react';
 import { saleService, customerService, filamentService, colorService } from '@/src/services/api';
 import { Customer, Sale, SaleItem, CreateSaleRequest } from '@/src/types/sales';
 import { Filament } from '@/src/types/filament';
+import { AdminSidebar } from '@/src/components/AdminSidebar';
 
 interface LineItem {
   filament_id: string;
@@ -120,50 +121,7 @@ export default function SalesPage() {
 
   return (
     <div className="min-h-screen bg-gray-50 dark:bg-gray-900 flex">
-      {/* Sidebar */}
-      <div className="w-64 bg-white dark:bg-gray-800 shadow-lg h-screen sticky top-0">
-        <div className="p-6">
-          <h2 className="text-xl font-bold text-gray-900 dark:text-white mb-6">Admin Panel</h2>
-          <nav className="space-y-2">
-            <a
-              href="/dashboard"
-              className="block px-4 py-2 text-gray-700 dark:text-gray-300 hover:bg-gray-100 dark:hover:bg-gray-700 rounded"
-            >
-              Filamenti
-            </a>
-            <a
-              href="/upadaj/colors"
-              className="block px-4 py-2 text-gray-700 dark:text-gray-300 hover:bg-gray-100 dark:hover:bg-gray-700 rounded"
-            >
-              Boje
-            </a>
-            <a
-              href="/upadaj/requests"
-              className="block px-4 py-2 text-gray-700 dark:text-gray-300 hover:bg-gray-100 dark:hover:bg-gray-700 rounded"
-            >
-              Zahtevi za boje
-            </a>
-            <a
-              href="/upadaj/sales"
-              className="block px-4 py-2 bg-blue-100 dark:bg-blue-900 text-blue-700 dark:text-blue-300 rounded"
-            >
-              Prodaja
-            </a>
-            <a
-              href="/upadaj/customers"
-              className="block px-4 py-2 text-gray-700 dark:text-gray-300 hover:bg-gray-100 dark:hover:bg-gray-700 rounded"
-            >
-              Kupci
-            </a>
-            <a
-              href="/upadaj/analytics"
-              className="block px-4 py-2 text-gray-700 dark:text-gray-300 hover:bg-gray-100 dark:hover:bg-gray-700 rounded"
-            >
-              Analitika
-            </a>
-          </nav>
-        </div>
-      </div>
+      <AdminSidebar />
 
       {/* Main Content */}
       <div className="flex-1 p-8">