Use Window Controls Overlay for Chrome PWA titlebar

Adds display_override: window-controls-overlay to the manifest so
the app extends into the titlebar area. The navbar becomes draggable
and uses env(titlebar-area-*) to avoid the window controls buttons.
Interactive elements stay clickable via -webkit-app-region: no-drag.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

static/css/app.css

@@ -98,6 +98,14 @@ a:hover {
   padding: 0 1.5rem;
   background: var(--bg);
   border-bottom: 1px solid var(--border);
+  /* Window Controls Overlay: extend navbar into the titlebar area */
+  padding-left: max(1.5rem, env(titlebar-area-x, 1.5rem));
+  padding-top: env(titlebar-area-y, 0);
+  height: calc(var(--nav-h) + env(titlebar-area-y, 0px));
+  -webkit-app-region: drag;
+}
+.navbar a, .navbar button, .navbar input, .navbar form {
+  -webkit-app-region: no-drag;
 }
 
 .navbar-brand {

static/manifest.json

@@ -4,6 +4,7 @@
   "description": "Internet radio player",
   "start_url": "/",
   "display": "standalone",
+  "display_override": ["window-controls-overlay", "standalone"],
   "background_color": "#000000",
   "theme_color": "#000000",
   "orientation": "any",