backup: Phase 6 search and export fixes before cleanup

- Added search button to main page header with Ctrl+K listener
- Implemented SearchModal component rendering
- Fixed SearchModal to use axiosInstance with correct backend URL (8916)
- Fixed token key from 'auth_token' to 'inventory_token'
- Verified export endpoints working correctly
- All Phase 6 UAT fixes in place

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

frontend/components/inventory/SearchModal.tsx

@@ -3,6 +3,7 @@
 import { useState, useEffect, useRef, useCallback } from 'react';
 import { X, Search } from 'lucide-react';
 import { Item } from '@/lib/db';
+import { axiosInstance } from '@/lib/api';
 
 interface SearchModalProps {
   isOpen: boolean;
@@ -41,22 +42,11 @@ export default function SearchModal({
     setError(null);
 
     try {
-      const backendUrl = process.env.NEXT_PUBLIC_BACKEND_URL || 'http://localhost:8906';
-      const token = localStorage.getItem('auth_token');
-      const response = await fetch(`${backendUrl}/items/search?q=${encodeURIComponent(searchQuery)}`, {
-        method: 'GET',
-        headers: {
-          'Content-Type': 'application/json',
-          'Authorization': `Bearer ${token}`
-        },
+      const response = await axiosInstance.get('/items/search', {
+        params: { q: searchQuery }
       });
 
-      if (!response.ok) {
-        throw new Error('Search failed');
-      }
-
-      const data = await response.json();
-      setResults(data || []);
+      setResults(response.data || []);
     } catch (err) {
       const errorMsg = err instanceof Error ? err.message : 'Search failed';
       setError(errorMsg);