refactor: migrate from react-hot-toast to react-toastify and replace all emoji icons with Lucide React

- Replaced react-hot-toast with react-toastify (ToastContainer in providers.tsx)
- Removed @heroicons/react dependency
- Added lucide-react for consistent SVG icon system
- Migrated all 18 frontend pages from emoji icons to Lucide components
- Updated sidebar navigation, login/register, dashboard, apps, deploy,
  tickets, admin users/clusters/pools pages
- All emoji indicators (status, runtime, actions) now use proper SVG icons
- Build passes with zero TypeScript errors

frontend/src/app/dashboard/admin/pools/page.tsx

@@ -3,8 +3,9 @@
 import { useState } from 'react';
 import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
 import api from '@/lib/api';
-import toast from 'react-hot-toast';
+import { toast } from 'react-toastify';
 import type { Cluster, ClusterPool } from '@/types';
+import { Scale, BarChart3, RotateCw, CheckCircle, XCircle, Pencil, Clock, X } from 'lucide-react';
 
 export default function AdminPoolsPage() {
   const queryClient = useQueryClient();
@@ -107,7 +108,7 @@ export default function AdminPoolsPage() {
           onClick={() => { showForm ? resetForm() : setShowForm(true); }}
           className={showForm ? 'btn-ghost' : 'btn-primary'}
         >
-          {showForm ? '✕ Cancel' : '+ Create Pool'}
+          {showForm ? <><X className="w-4 h-4 inline" /> Cancel</> : '+ Create Pool'}
         </button>
       </div>
 
@@ -135,8 +136,8 @@ export default function AdminPoolsPage() {
                 value={form.strategy}
                 onChange={(e) => setForm({ ...form, strategy: e.target.value as any })}
               >
-                <option value="least-apps">📊 Least Apps — deploy to cluster with fewest apps</option>
-                <option value="round-robin">🔄 Round Robin — rotate across clusters evenly</option>
+                <option value="least-apps">Least Apps — deploy to cluster with fewest apps</option>
+                <option value="round-robin">Round Robin — rotate across clusters evenly</option>
               </select>
             </div>
           </div>
@@ -223,7 +224,7 @@ export default function AdminPoolsPage() {
               className="btn-primary disabled:opacity-50"
             >
               {createMutation.isPending || updateMutation.isPending
-                ? '⏳ Saving...'
+                ? <><Clock className="w-4 h-4 inline animate-spin" /> Saving...</>
                 : editingPool
                 ? 'Update Pool'
                 : 'Create Pool'}
@@ -254,7 +255,7 @@ export default function AdminPoolsPage() {
         </div>
       ) : pools.length === 0 ? (
         <div className="card text-center py-16">
-          <div className="text-5xl mb-4">⚖️</div>
+          <Scale className="w-12 h-12 mx-auto text-gray-300 mb-4" />
           <p className="text-gray-600 font-medium">No cluster pools created yet</p>
           <p className="text-sm text-gray-400 mt-1">
             Create a pool to enable load-balanced deployment across multiple clusters
@@ -274,8 +275,8 @@ export default function AdminPoolsPage() {
                       <span className={`badge ${pool.isActive ? 'badge-green' : 'badge-gray'}`}>
                         {pool.isActive ? 'Active' : 'Inactive'}
                       </span>
-                      <span className="badge badge-purple">
-                        {pool.strategy === 'least-apps' ? '📊 Least Apps' : '🔄 Round Robin'}
+                      <span className="badge badge-purple flex items-center gap-1">
+                        {pool.strategy === 'least-apps' ? <><BarChart3 className="w-3 h-3" /> Least Apps</> : <><RotateCw className="w-3 h-3" /> Round Robin</>}
                       </span>
                     </div>
                     {pool.description && (
@@ -293,7 +294,7 @@ export default function AdminPoolsPage() {
                               : 'bg-red-50 text-red-700 border border-red-200'
                           }`}
                         >
-                          <span>{cluster.status === 'active' ? '✅' : '❌'}</span>
+                          <span>{cluster.status === 'active' ? <CheckCircle className="w-3 h-3" /> : <XCircle className="w-3 h-3" />}</span>
                           <span>{cluster.name}</span>
                           <span className="text-gray-400">
                             ({cluster.provider || 'N/A'} · {cluster.region || 'N/A'})
@@ -314,7 +315,7 @@ export default function AdminPoolsPage() {
                       onClick={() => startEdit(pool)}
                       className="btn-ghost text-sm"
                     >
-                      ✏️ Edit
+                      <Pencil className="w-3 h-3 inline" /> Edit
                     </button>
                     <button
                       onClick={() => {