release: v4.9.1 — redesigned QR scanner, UI fixes, README overhaul

UI / design
- Rework the camera scan modal to the new "Start Secure" design: green
  viewfinder with corner brackets, animated scan line, spinner + live
  frame counter, and a blurred dark backdrop. Keep the Html5Qrcode
  #qr-reader video feed, styled to fill the square viewfinder.
- Fix Advanced (network) settings: the fixed landing header (z-50) was
  covering the panel's close button — raise the embedded overlay to z-60.
- Stack the connection-screen footer buttons ("Download desktop app" /
  "Advanced settings") full-width on mobile and tablet instead of in a row.

Docs
- Rewrite README to follow GitHub best practices: capability-oriented
  Features, How it works, and Security model sections; move release notes
  out of the README and point to CHANGELOG.md. Keep logo and screenshots.

Chore
- Bump version to 4.9.1 (header, package.json, manifest) and rebuild bundles.

index.html

@@ -23,7 +23,7 @@
 
     <!-- PWA Manifest -->
 <link rel="manifest" href="./manifest.json">
-<link rel="icon" type="image/x-icon" href="./logo/favicon.ico?v=1782247921955">
+<link rel="icon" type="image/x-icon" href="./logo/favicon.ico?v=1782329449554">
 
 <!-- PWA Meta Tags -->
 <meta name="mobile-web-app-capable" content="yes">
@@ -89,7 +89,7 @@
     <link rel="apple-touch-startup-image" media="screen and (device-width: 744px) and (device-height: 1133px) and (-webkit-device-pixel-ratio: 2) and (orientation: portrait)" href="./logo/splash/splash_screens/8.3__iPad_Mini_portrait.png">
     
 <!-- Apple Touch Icons -->
-<link rel="apple-touch-icon" href="./logo/icon-180x180.png?v=1782247921955">
+<link rel="apple-touch-icon" href="./logo/icon-180x180.png?v=1782329449554">
 <link rel="apple-touch-icon" sizes="57x57" href="./logo/icon-57x57.png">
 <link rel="apple-touch-icon" sizes="60x60" href="./logo/icon-60x60.png">
 <link rel="apple-touch-icon" sizes="72x72" href="./logo/icon-72x72.png">
@@ -98,7 +98,7 @@
 <link rel="apple-touch-icon" sizes="120x120" href="./logo/icon-120x120.png">
 <link rel="apple-touch-icon" sizes="144x144" href="./logo/icon-144x144.png">
 <link rel="apple-touch-icon" sizes="152x152" href="./logo/icon-152x152.png">
-<link rel="apple-touch-icon" sizes="180x180" href="./logo/icon-180x180.png?v=1782247921955">
+<link rel="apple-touch-icon" sizes="180x180" href="./logo/icon-180x180.png?v=1782329449554">
 
 <!-- Microsoft Tiles -->
 <meta name="msapplication-TileColor" content="#ff6b35">
@@ -134,32 +134,32 @@
     <script src="config/ice-servers.js"></script>
     <script src="libs/react/react.production.min.js"></script>
     <script src="libs/react-dom/react-dom.production.min.js"></script>
-    <link rel="stylesheet" href="assets/tailwind.css?v=1782247921955">
-    <link rel="icon" type="image/x-icon" href="/logo/favicon.ico?v=1782247921955">
+    <link rel="stylesheet" href="assets/tailwind.css?v=1782329449554">
+    <link rel="icon" type="image/x-icon" href="/logo/favicon.ico?v=1782329449554">
     <link rel="stylesheet" href="/assets/fontawesome/css/all.min.css">
     <link rel="preload" href="/assets/fontawesome/webfonts/fa-solid-900.woff2" as="font" type="font/woff2" crossorigin>
     <link rel="preload" href="/assets/fontawesome/webfonts/fa-regular-400.woff2" as="font" type="font/woff2" crossorigin>
     <link rel="preload" href="/assets/fontawesome/webfonts/fa-brands-400.woff2" as="font" type="font/woff2" crossorigin>
     <link rel="stylesheet" href="/assets/fonts/inter/inter.css">
-    <link rel="stylesheet" href="src/styles/main.css?v=1782247921955">
-    <link rel="stylesheet" href="src/styles/animations.css?v=1782247921955">
-    <link rel="stylesheet" href="src/styles/components.css?v=1782247921955">
-    <script src="src/scripts/fa-check.js?v=1782247921955"></script>
+    <link rel="stylesheet" href="src/styles/main.css?v=1782329449554">
+    <link rel="stylesheet" href="src/styles/animations.css?v=1782329449554">
+    <link rel="stylesheet" href="src/styles/components.css?v=1782329449554">
+    <script src="src/scripts/fa-check.js?v=1782329449554"></script>
     <!-- Update Manager - система принудительного обновления -->
-    <script src="src/utils/updateManager.js?v=1782247921955"></script>
-    <script type="module" src="src/components/UpdateChecker.jsx?v=1782247921955"></script>
-    <script type="module" src="dist/qr-local.js?v=1782247921955"></script>
-    <script type="module" src="src/components/QRScanner.js?v=1782247921955"></script>
+    <script src="src/utils/updateManager.js?v=1782329449554"></script>
+    <script type="module" src="src/components/UpdateChecker.jsx?v=1782329449554"></script>
+    <script type="module" src="dist/qr-local.js?v=1782329449554"></script>
+    <script type="module" src="src/components/QRScanner.js?v=1782329449554"></script>
 </head>
 <body>
     <div id="root"></div>
-    <script type="module" src="dist/app-boot.js?v=1782247921955"></script>
-    <script type="module" src="dist/app.js?v=1782247921955"></script>
+    <script type="module" src="dist/app-boot.js?v=1782329449554"></script>
+    <script type="module" src="dist/app.js?v=1782329449554"></script>
 
-<script src="src/scripts/pwa-register.js?v=1782247921955"></script>
-<script src="./src/pwa/install-prompt.js?v=1782247921955" type="module"></script>
-<script src="./src/pwa/pwa-manager.js?v=1782247921955" type="module"></script>
-<script src="./src/scripts/pwa-offline-test.js?v=1782247921955"></script>
-<link rel="stylesheet" href="./src/styles/pwa.css?v=1782247921955">
+<script src="src/scripts/pwa-register.js?v=1782329449554"></script>
+<script src="./src/pwa/install-prompt.js?v=1782329449554" type="module"></script>
+<script src="./src/pwa/pwa-manager.js?v=1782329449554" type="module"></script>
+<script src="./src/scripts/pwa-offline-test.js?v=1782329449554"></script>
+<link rel="stylesheet" href="./src/styles/pwa.css?v=1782329449554">
 </body>
 </html>