feat: add app favicon and startup loading overlay animation

cypher-chat-app/public/app.js

@@ -60,6 +60,15 @@ document.addEventListener("DOMContentLoaded", () => {
     }
     
     setupEventListeners();
+
+    // Hide startup loader smoothly
+    const loader = document.getElementById("startupLoader");
+    if (loader) {
+        setTimeout(() => {
+            loader.classList.add("fade-out");
+            setTimeout(() => loader.remove(), 600);
+        }, 1500); // 1.5 seconds premium delay
+    }
 });
 
 // Settings & Theme Initialization

cypher-chat-app/public/index.html

@@ -4,6 +4,7 @@
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no">
     <title>Cypher AI — Chat App</title>
+    <link rel="icon" type="image/png" href="logo.png">
     <link rel="stylesheet" href="style.css">
     <!-- Google Fonts -->
     <link href="https://fonts.googleapis.com/css2?family=Outfit:wght@300;400;600;700;800&family=JetBrains+Mono:wght@400;700&display=swap" rel="stylesheet">
@@ -11,6 +12,18 @@
     <script src="https://unpkg.com/lucide@latest"></script>
 </head>
 <body>
+    <!-- Startup loading screen -->
+    <div class="startup-loader" id="startupLoader">
+        <div class="loader-content">
+            <img src="logo.png" alt="Cypher AI Logo" class="loader-logo">
+            <h2 class="loader-title">CYPHER AI</h2>
+            <div class="loader-bar-container">
+                <div class="loader-bar"></div>
+            </div>
+            <p class="loader-subtitle">Chargement des modules d'élite...</p>
+        </div>
+    </div>
+
     <div class="app-container">
         <!-- Sidebar Panel -->
         <aside class="sidebar" id="sidebar">

cypher-chat-app/public/style.css

@@ -1285,3 +1285,93 @@ input:checked + .slider:before {
     to { opacity: 0; transform: scale(0.95); }
 }
 
+/* -----------------------------------------------------
+   STARTUP LOADER OVERLAY
+   ----------------------------------------------------- */
+.startup-loader {
+    position: fixed;
+    top: 0;
+    left: 0;
+    width: 100vw;
+    height: 100vh;
+    background-color: var(--bg-app);
+    background-image: var(--bg-gradient);
+    z-index: 99999;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    transition: opacity 0.6s ease, transform 0.6s ease;
+}
+
+.startup-loader.fade-out {
+    opacity: 0;
+    pointer-events: none;
+    transform: scale(1.05);
+}
+
+.loader-content {
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    text-align: center;
+}
+
+.loader-logo {
+    width: 96px;
+    height: 96px;
+    border-radius: 16px;
+    border: 2px solid var(--accent-cyan);
+    box-shadow: 0 0 30px rgba(0, 229, 255, 0.35);
+    margin-bottom: 20px;
+    animation: pulseLogo 2s infinite ease-in-out;
+}
+
+.loader-title {
+    font-size: 24px;
+    font-weight: 800;
+    letter-spacing: 2px;
+    background: linear-gradient(90deg, var(--accent-cyan), var(--accent-green));
+    -webkit-background-clip: text;
+    -webkit-text-fill-color: transparent;
+    margin-bottom: 16px;
+}
+
+.loader-bar-container {
+    width: 200px;
+    height: 4px;
+    background: rgba(30, 34, 53, 0.5);
+    border-radius: 2px;
+    overflow: hidden;
+    margin-bottom: 12px;
+    border: 1px solid rgba(255,255,255,0.05);
+}
+
+.loader-bar {
+    width: 0%;
+    height: 100%;
+    background: linear-gradient(90deg, var(--accent-cyan), var(--accent-green));
+    box-shadow: 0 0 10px var(--accent-cyan);
+    animation: loadProgress 1.4s ease-out forwards;
+}
+
+.loader-subtitle {
+    font-size: 11px;
+    color: var(--text-muted);
+    font-weight: 600;
+    text-transform: uppercase;
+    letter-spacing: 1px;
+}
+
+@keyframes pulseLogo {
+    0% { transform: scale(1); box-shadow: 0 0 20px rgba(0, 229, 255, 0.2); }
+    50% { transform: scale(1.04); box-shadow: 0 0 35px rgba(0, 229, 255, 0.45); }
+    100% { transform: scale(1); box-shadow: 0 0 20px rgba(0, 229, 255, 0.2); }
+}
+
+@keyframes loadProgress {
+    0% { width: 0%; }
+    20% { width: 30%; }
+    60% { width: 75%; }
+    100% { width: 100%; }
+}
+