security: fix SAS verification bypass and unauthenticated frame injection; release v5.5.2

A security review of the transport and verification layers. Every item is a fix
to how untrusted peer input is handled; no features changed.

- SAS verification could be bypassed. `verification_both_confirmed` is an
  unauthenticated frame on a channel that is not yet trusted, but it was taken as
  proof that both sides had compared their codes — so a peer who completed the
  signalling exchange could send it right after the data channel opened and drive
  the other side to a "verified" session while the user never looked at the code.
  It is now only an acknowledgement: refused unless this side already confirmed
  locally, and _setVerifiedStatus() independently rejects any SAS-based
  transition without a local confirmation. Holding ECDH-derived keys was never
  proof of identity — a MITM has those too.

- Unauthenticated frames could be injected into the chat. A bare
  {type:"message"} frame, a raw non-JSON frame and a binary frame were each
  decoded and rendered, bypassing decryption, the HMAC check and the verification
  gate; the injected text was indistinguishable from a genuine message. Chat
  content now reaches the UI only through the authenticated enhanced_message
  path.

- A peer could supply the verification code. `sas_code` announcements were
  adopted verbatim when no local SAS had been derived yet. They may now only
  corroborate the locally derived code.

- Anti-replay never ran. The sequence-number and AAD validators were defined on
  SecureKeyStorage instead of the connection manager, so every call site failed
  with a TypeError and the sliding replay window was dead code. Moved onto the
  manager, wired into the live chat path, and a missing or non-numeric sequence
  number now fails closed instead of sailing through the range checks.

- File transfers are gated on verification in both directions. Control frames are
  written straight to the data channel by the transfer system; sending was
  already gated, receiving now is too.

- Tighter CSP: connect-src and img-src no longer allow arbitrary https: hosts
  (nothing in the app talks to a third party), plus base-uri 'none'.

- The SAS is no longer written to logs, and is compared in constant time on every
  path. Fixed SecureMasterKeyManager.isUnlocked() testing a field renamed long
  ago, so it never actually gated anything.

- Fixed the header showing "Secure undefined%": getRealSecurityLevel() became
  reachable for the first time by the move above and returned only per-feature
  booleans, while the header renders `level` and `score` directly. It now runs
  the same verified scoring as every other consumer.

Adds regression tests for the verification gate, inbound frame authentication and
the security-level shape.

index.html

@@ -8,14 +8,15 @@
            script-src 'self';
            style-src 'self' 'unsafe-inline';
            font-src 'self' data:;
-           connect-src 'self' https: wss: ws: stun: stuns: turn: turns:;
-           img-src 'self' data: https:;
+           connect-src 'self' stun: stuns: turn: turns:;
+           img-src 'self' data:;
            media-src 'self' blob:;
            object-src 'none';
            frame-src 'none';
            worker-src 'self';
            manifest-src 'self';
            form-action 'self';
+           base-uri 'none';
            upgrade-insecure-requests;">
     <meta http-equiv="X-Content-Type-Options" content="nosniff">
     <meta http-equiv="X-XSS-Protection" content="1; mode=block">
@@ -23,7 +24,7 @@
 
     <!-- PWA Manifest -->
 <link rel="manifest" href="./manifest.json">
-<link rel="icon" type="image/x-icon" href="./logo/favicon.ico?v=1784825757783">
+<link rel="icon" type="image/x-icon" href="./logo/favicon.ico?v=1785125039593">
 
 <!-- PWA Meta Tags -->
 <meta name="mobile-web-app-capable" content="yes">
@@ -89,7 +90,7 @@
     <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=1784825757783">
+<link rel="apple-touch-icon" href="./logo/icon-180x180.png?v=1785125039593">
 <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 +99,7 @@
 <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=1784825757783">
+<link rel="apple-touch-icon" sizes="180x180" href="./logo/icon-180x180.png?v=1785125039593">
 
 <!-- Microsoft Tiles -->
 <meta name="msapplication-TileColor" content="#ff6b35">
@@ -182,7 +183,7 @@
     <!-- Render-blocking JS is deferred: classic deferred scripts and module scripts
          both execute in document order after parsing, so React still runs before the
          app modules below, but the parser / first paint is no longer blocked. -->
-    <script defer src="config/ice-servers.js?v=1784825757783"></script>
+    <script defer src="config/ice-servers.js?v=1785125039593"></script>
     <script defer src="libs/react/react.production.min.js"></script>
     <script defer src="libs/react-dom/react-dom.production.min.js"></script>
     <!-- Prism syntax highlighting (vendored, offline). Tokenizes code as TEXT only —
@@ -190,8 +191,8 @@
          Its CSS is loaded async via load-async-css.js (not paint-critical). -->
     <script defer src="libs/prism/prism.js"></script>
     <!-- Critical, paint-defining CSS stays render-blocking (avoids FOUC / layout shift). -->
-    <link rel="stylesheet" href="assets/tailwind.css?v=1784825757783">
-    <link rel="icon" type="image/x-icon" href="/logo/favicon.ico?v=1784825757783">
+    <link rel="stylesheet" href="assets/tailwind.css?v=1785125039593">
+    <link rel="icon" type="image/x-icon" href="/logo/favicon.ico?v=1785125039593">
     <!-- Preload only the fonts needed for first paint. fa-solid covers the bulk of UI
          icons; fa-regular/fa-brands are loaded on demand by their CSS (rarely on the
          first screen). Inter latin 400/700 cover body text and headings/buttons. -->
@@ -199,31 +200,31 @@
     <link rel="preload" href="/assets/fonts/inter/files/inter-latin-400.woff2" as="font" type="font/woff2" crossorigin>
     <link rel="preload" href="/assets/fonts/inter/files/inter-latin-700.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=1784825757783">
-    <link rel="stylesheet" href="src/styles/animations.css?v=1784825757783">
-    <link rel="stylesheet" href="src/styles/components.css?v=1784825757783">
+    <link rel="stylesheet" href="src/styles/main.css?v=1785125039593">
+    <link rel="stylesheet" href="src/styles/animations.css?v=1785125039593">
+    <link rel="stylesheet" href="src/styles/components.css?v=1785125039593">
     <!-- Non-critical CSS (FontAwesome ~102KB, Prism) loaded async — no longer blocks paint. -->
-    <script defer src="src/scripts/load-async-css.js?v=1784825757783"></script>
+    <script defer src="src/scripts/load-async-css.js?v=1785125039593"></script>
     <noscript>
         <link rel="stylesheet" href="/assets/fontawesome/css/all.min.css">
         <link rel="stylesheet" href="libs/prism/prism.css">
     </noscript>
-    <script defer src="src/scripts/fa-check.js?v=1784825757783"></script>
+    <script defer src="src/scripts/fa-check.js?v=1785125039593"></script>
     <!-- Update Manager - система принудительного обновления -->
-    <script defer src="src/utils/updateManager.js?v=1784825757783"></script>
-    <script type="module" src="src/components/UpdateChecker.jsx?v=1784825757783"></script>
-    <script type="module" src="dist/qr-local.js?v=1784825757783"></script>
-    <script type="module" src="src/components/QRScanner.js?v=1784825757783"></script>
+    <script defer src="src/utils/updateManager.js?v=1785125039593"></script>
+    <script type="module" src="src/components/UpdateChecker.jsx?v=1785125039593"></script>
+    <script type="module" src="dist/qr-local.js?v=1785125039593"></script>
+    <script type="module" src="src/components/QRScanner.js?v=1785125039593"></script>
 </head>
 <body>
     <div id="root"></div>
-    <script type="module" src="dist/app-boot.js?v=1784825757783"></script>
-    <script type="module" src="dist/app.js?v=1784825757783"></script>
+    <script type="module" src="dist/app-boot.js?v=1785125039593"></script>
+    <script type="module" src="dist/app.js?v=1785125039593"></script>
 
-<script defer src="src/scripts/pwa-register.js?v=1784825757783"></script>
-<script src="./src/pwa/install-prompt.js?v=1784825757783" type="module"></script>
-<script src="./src/pwa/pwa-manager.js?v=1784825757783" type="module"></script>
-<script defer src="./src/scripts/pwa-offline-test.js?v=1784825757783"></script>
-<link rel="stylesheet" href="./src/styles/pwa.css?v=1784825757783">
+<script defer src="src/scripts/pwa-register.js?v=1785125039593"></script>
+<script src="./src/pwa/install-prompt.js?v=1785125039593" type="module"></script>
+<script src="./src/pwa/pwa-manager.js?v=1785125039593" type="module"></script>
+<script defer src="./src/scripts/pwa-offline-test.js?v=1785125039593"></script>
+<link rel="stylesheet" href="./src/styles/pwa.css?v=1785125039593">
 </body>
 </html>