Redesign configurator UI with tabs and remove Excel export

- Add tab-based configurator (Base, Storage, PCI, Power, Accessories, Other)
- Base tab: single-select with autocomplete for MB, CPU, MEM
- Other tabs: multi-select with autocomplete and quantity input
- Table view with LOT, Description, Price, Quantity, Total columns
- Add configuration list page with create modal (opportunity number)
- Remove Excel export functionality and excelize dependency
- Increase component list limit from 100 to 5000
- Add web templates (base, index, configs, login, admin_pricing)

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

web/templates/login.html

@@ -0,0 +1,82 @@
+{{define "title"}}Вход - QuoteForge{{end}}
+
+{{define "content"}}
+<div class="max-w-sm mx-auto mt-16">
+    <div class="bg-white rounded-lg shadow p-6">
+        <h1 class="text-xl font-bold text-center mb-6">Вход в систему</h1>
+
+        <form id="login-form">
+            <div class="mb-4">
+                <label class="block text-sm font-medium text-gray-700 mb-1">Логин</label>
+                <input type="text" name="username" id="username" required
+                       class="w-full px-3 py-2 border rounded focus:outline-none focus:ring-2 focus:ring-blue-500"
+                       value="admin">
+            </div>
+            <div class="mb-4">
+                <label class="block text-sm font-medium text-gray-700 mb-1">Пароль</label>
+                <input type="password" name="password" id="password" required
+                       class="w-full px-3 py-2 border rounded focus:outline-none focus:ring-2 focus:ring-blue-500"
+                       value="admin123">
+            </div>
+            <div id="error" class="text-red-600 text-sm mb-4 hidden"></div>
+            <button type="submit" id="submit-btn"
+                    class="w-full bg-blue-600 text-white py-2 rounded hover:bg-blue-700">
+                Войти
+            </button>
+        </form>
+
+        <p class="text-center text-sm text-gray-500 mt-4">
+            <a href="/" class="text-blue-600">← На главную</a>
+        </p>
+    </div>
+</div>
+
+<script>
+document.addEventListener('DOMContentLoaded', function() {
+    const form = document.getElementById('login-form');
+    if (!form) return;
+
+    form.addEventListener('submit', async function(e) {
+        e.preventDefault();
+
+        const username = document.getElementById('username').value;
+        const password = document.getElementById('password').value;
+        const errorEl = document.getElementById('error');
+        const btn = document.getElementById('submit-btn');
+
+        errorEl.classList.add('hidden');
+        btn.disabled = true;
+        btn.textContent = 'Вход...';
+
+        try {
+            const resp = await fetch('/api/auth/login', {
+                method: 'POST',
+                headers: {'Content-Type': 'application/json'},
+                body: JSON.stringify({username, password})
+            });
+
+            const data = await resp.json();
+
+            if (resp.ok && data.access_token) {
+                localStorage.setItem('token', data.access_token);
+                localStorage.setItem('refresh_token', data.refresh_token);
+                localStorage.setItem('user', JSON.stringify(data.user));
+                window.location.href = '/configs';
+            } else {
+                errorEl.textContent = data.error || 'Неверный логин или пароль';
+                errorEl.classList.remove('hidden');
+                btn.disabled = false;
+                btn.textContent = 'Войти';
+            }
+        } catch(err) {
+            errorEl.textContent = 'Ошибка соединения с сервером';
+            errorEl.classList.remove('hidden');
+            btn.disabled = false;
+            btn.textContent = 'Войти';
+        }
+    });
+});
+</script>
+{{end}}
+
+{{template "base" .}}