feat: add release notes overlay with Markdown rendering

- Replace truncated plaintext release notes with full-screen overlay
  rendered via `marked` library
- Server reconnection does a hard page reload instead of custom event

server/src/wled_controller/templates/modals/settings.html

@@ -239,12 +239,9 @@
                     </div>
                 </div>
 
-                <!-- Release notes preview -->
-                <div class="form-group" style="display:none">
-                    <div class="label-row">
-                        <label data-i18n="update.release_notes">Release Notes</label>
-                    </div>
-                    <pre id="update-release-notes" style="max-height:200px;overflow-y:auto;font-size:0.82rem;white-space:pre-wrap;word-break:break-word;padding:0.5rem;background:var(--bg-secondary);border-radius:var(--radius-sm);border:1px solid var(--border-color);"></pre>
+                <!-- Release notes button -->
+                <div class="form-group" id="update-release-notes-group" style="display:none">
+                    <button class="btn btn-secondary" onclick="openReleaseNotes()" style="width:100%" data-i18n="update.view_release_notes">View Release Notes</button>
                 </div>
 
                 <!-- Settings -->
@@ -309,3 +306,12 @@
     </div>
     <pre id="log-viewer-output" class="log-viewer-output"></pre>
 </div>
+
+<!-- Release Notes Overlay (full-screen, same pattern as log overlay) -->
+<div id="release-notes-overlay" class="log-overlay" style="display:none;">
+    <button class="log-overlay-close" onclick="closeReleaseNotes()" title="Close" data-i18n-aria-label="aria.close">&#x2715;</button>
+    <div class="log-overlay-toolbar">
+        <h3 data-i18n="update.release_notes">Release Notes</h3>
+    </div>
+    <div id="release-notes-content" class="release-notes-content"></div>
+</div>