Add LLM endpoints, web frontend, and rate limiting config

- Added OpenAI-compatible LLM endpoints to API backend - Introduced web
frontend with Jinja2 templates and static assets - Implemented API proxy
routes in web service - Added sample db.json data for items, users,
orders, reviews, categories, llm_requests - Updated ADC and Helm configs
for separate AI and standard rate limiting - Upgraded FastAPI, Uvicorn,
and added httpx, Jinja2, python-multipart dependencies - Added API
configuration modal and client-side JS for web app

web/templates/users.html

@@ -0,0 +1,69 @@
+{% extends "base.html" %}
+
+{% block title %}Users - API Demo{% endblock %}
+
+{% block content %}
+<div class="page-header">
+    <h1>👥 Users</h1>
+    <p>Manage user accounts</p>
+</div>
+
+<div class="table-container">
+    <table class="data-table">
+        <thead>
+            <tr>
+                <th>ID</th>
+                <th>Username</th>
+                <th>Email</th>
+                <th>Status</th>
+                <th>Actions</th>
+            </tr>
+        </thead>
+        <tbody id="users-table-body">
+            <tr>
+                <td colspan="5" class="loading">Loading users...</td>
+            </tr>
+        </tbody>
+    </table>
+</div>
+{% endblock %}
+
+{% block scripts %}
+<script>
+const API_BASE = '/api';
+
+async function loadUsers() {
+    try {
+        const response = await fetch(`${API_BASE}/users`);
+        const users = await response.json();
+
+        const tbody = document.getElementById('users-table-body');
+        tbody.innerHTML = users.map(user => `
+            <tr>
+                <td>${user.id}</td>
+                <td>${user.username}</td>
+                <td>${user.email}</td>
+                <td>
+                    <span class="badge ${user.active ? 'badge-success' : 'badge-danger'}">
+                        ${user.active ? 'Active' : 'Inactive'}
+                    </span>
+                </td>
+                <td>
+                    <button class="btn btn-sm" onclick="viewUser(${user.id})">View</button>
+                </td>
+            </tr>
+        `).join('');
+    } catch (error) {
+        console.error('Error loading users:', error);
+        document.getElementById('users-table-body').innerHTML =
+            '<tr><td colspan="5" class="error">Failed to load users</td></tr>';
+    }
+}
+
+function viewUser(id) {
+    alert(`View user details for ID: ${id}\n\nAPI Endpoint: /api/users/${id}`);
+}
+
+loadUsers();
+</script>
+{% endblock %}