fix(theme): correct sticky rail selector, harden bool attrs/tests, doc LoginCard security contract

- layout.css: fix @media sticky selector from #sidebar-collapse → #theme-rail (Fix 1)
- NavRailTests/CommonControlsTests: add TDD tests verifying Blazor omits false bool attrs (Fix 2)
- TechButton: rename Extra → AdditionalAttributes, move @attributes splat first (Fix 3)
- LoginCard: add security contract XML/comment docs on ReturnUrl and ChildContent (Fix 4)
- build/pack.sh, push.sh: fix comment from ZB.MOM.WW.Auth → ZB.MOM.WW.Theme (Fix 5)

ZB.MOM.WW.Theme/build/pack.sh

@@ -1,5 +1,5 @@
 #!/usr/bin/env bash
-# pack.sh — produce the ZB.MOM.WW.Auth NuGet packages into ./artifacts.
+# pack.sh — produce the ZB.MOM.WW.Theme NuGet packages into ./artifacts.
 #
 # Usage:
 #   ./build/pack.sh

ZB.MOM.WW.Theme/build/push.sh

@@ -1,5 +1,5 @@
 #!/usr/bin/env bash
-# push.sh — pack and push all ZB.MOM.WW.Auth NuGet packages to the Gitea feed.
+# push.sh — pack and push all ZB.MOM.WW.Theme NuGet packages to the Gitea feed.
 #
 # Required environment variables:
 #   GITEA_NUGET_SOURCE  — full URL of the Gitea NuGet feed