Move Windows camera help into overlay

The privacy instructions no longer bloat the launcher card.
A "Help" button in the navbar opens them in a native dialog
(Esc, backdrop and button close it). The button only shows
for Windows users, reusing the existing OS detection.

Translations may contain <kbd>, <b> and <i> markup now. The
renderer builds nodes from a tag whitelist instead of using
innerHTML, so smuggled tags from i18n.json cannot execute.

All help texts live under meetingPrivacySettings.windows;
sibling keys for other operating systems can follow.

launch.html

@@ -33,6 +33,9 @@
       <a id="legalNoticeLink" class="button secondary hidden" href="#" target="_blank" rel="noopener noreferrer" data-i18n="legal_notice">
         Legal Notice
       </a>
+      <button id="windowsHelpButton" class="button secondary hidden" type="button" data-i18n="meetingPrivacySettings.windows.navButton">
+        Help
+      </button>
       <a class="button secondary" href="https://git.bnvb.eu/stefan.tollkuehn/jitsi-launch" target="_blank" rel="noopener noreferrer" data-i18n="source">
         Source
       </a>
@@ -83,32 +86,6 @@
           <button id="createNewFromLauncherButton" class="button secondary hidden" type="button" data-i18n="creator.createNewButton">
             Create New Meeting
           </button>
-
-          <!-- KAMERA-/MIKROFON-HINWEISE (WINDOWS) -->
-          <div id="privacyInfo" class="privacy hidden">
-            <h2 data-i18n="meetingPrivacySettings.title"></h2>
-            <p data-i18n="meetingPrivacySettings.intro"></p>
-
-            <h3 data-i18n="meetingPrivacySettings.step1Title"></h3>
-            <p data-i18n="meetingPrivacySettings.step1Description"></p>
-
-            <h3 data-i18n="meetingPrivacySettings.step2Title"></h3>
-            <p data-i18n="meetingPrivacySettings.step2Description"></p>
-
-            <h3 data-i18n="meetingPrivacySettings.step3Title"></h3>
-            <p data-i18n="meetingPrivacySettings.step3Description"></p>
-
-            <p data-i18n="meetingPrivacySettings.browserPermissions"></p>
-
-            <h3 data-i18n="meetingPrivacySettings.goodToKnowTitle"></h3>
-            <ul>
-              <li data-i18n="meetingPrivacySettings.goodToKnow1"></li>
-              <li data-i18n="meetingPrivacySettings.goodToKnow2"></li>
-              <li data-i18n="meetingPrivacySettings.goodToKnow3"></li>
-            </ul>
-
-            <p data-i18n="meetingPrivacySettings.adminSupport"></p>
-          </div>
         </div>
 
         <!-- STARTVORGANG -->
@@ -342,6 +319,39 @@
 
       </div>
     </div>
+
+    <!-- WINDOWS-HILFE OVERLAY -->
+    <dialog id="windowsHelpOverlay" class="privacy">
+      <h2 data-i18n="meetingPrivacySettings.windows.title"></h2>
+      <p data-i18n="meetingPrivacySettings.windows.intro"></p>
+
+      <h3 data-i18n="meetingPrivacySettings.windows.step1Title"></h3>
+      <p data-i18n="meetingPrivacySettings.windows.step1Description"></p>
+
+      <h3 data-i18n="meetingPrivacySettings.windows.step2Title"></h3>
+      <p data-i18n="meetingPrivacySettings.windows.step2Description"></p>
+
+      <h3 data-i18n="meetingPrivacySettings.windows.step3Title"></h3>
+      <p data-i18n="meetingPrivacySettings.windows.step3Description"></p>
+
+      <p data-i18n="meetingPrivacySettings.windows.browserPermissions"></p>
+
+      <h3 data-i18n="meetingPrivacySettings.windows.goodToKnowTitle"></h3>
+      <ul>
+        <li data-i18n="meetingPrivacySettings.windows.goodToKnow1"></li>
+        <li data-i18n="meetingPrivacySettings.windows.goodToKnow2"></li>
+        <li data-i18n="meetingPrivacySettings.windows.goodToKnow3"></li>
+      </ul>
+
+      <p data-i18n="meetingPrivacySettings.windows.adminSupport"></p>
+
+      <div class="help-actions">
+        <button id="windowsHelpClose" class="button secondary" type="button" data-i18n="meetingPrivacySettings.windows.closeButton">
+          Close
+        </button>
+      </div>
+    </dialog>
+
     <script src="assets/lib/ua-parser.min.js"></script>
     <script src="assets/launch.js"></script>
   </body>