fixing style

ui/app/index.html

@@ -3,8 +3,24 @@
   <head>
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-    <meta name="theme-color" content="#1e1e2e" />
+    <meta name="theme-color" content="#120826" />
     <title>Urpi's backlog</title>
+
+    <!--
+      The shared styling contract and its two controls are added to this shell by the
+      server, from CMS_THEME_BASE_URL. They are not written here because a build-time
+      placeholder has to survive two things that both break quietly: the bundler tries
+      to resolve a module URL at build time and fails the build, and an unset or
+      whitespace-only environment variable produces a relative URL that 404s on every
+      page load.
+
+      With the origin unset, nothing is added and the stylesheet's own fallbacks carry
+      the application: every colour in styles.css is written as
+      var(--bn-role, <the colour it used to be>), so the page renders exactly as it
+      did before the contract existed.
+
+      See internal/web/handlers.go, applyThemeOrigin.
+    -->
   </head>
   <body>
     <div id="root"></div>