fix(theme): .rise uses fill-mode backwards so it stops trapping position:fixed descendants (OtOpcUa #643)

Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe

ZB.MOM.WW.Theme/Directory.Build.props

@@ -4,7 +4,7 @@
     <Nullable>enable</Nullable>
     <ImplicitUsings>enable</ImplicitUsings>
     <LangVersion>latest</LangVersion>
-    <Version>0.4.1</Version>
+    <Version>0.4.2</Version>
     <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
   </PropertyGroup>
 </Project>

ZB.MOM.WW.Theme/src/ZB.MOM.WW.Theme/wwwroot/css/theme.css

@@ -225,7 +225,7 @@ a:hover { color: var(--accent-deep); text-decoration: underline; }
    Add .rise to top-level sections; stagger with inline animation-delay
    (.02s, .08s, .14s …) so panels settle in sequence, not all at once. */
 @keyframes rise { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }
-.rise { animation: rise 0.4s ease both; }
+.rise { animation: rise 0.4s ease backwards; /* backwards: end keyframe equals natural style, preventing a containing-block trap for position:fixed descendants */ }
 
 /* ════════════════════════════════════════════════════════════════════════════
    COMPONENT LIBRARY