Clarify non-content page detection in site shell

[Copilot]

isContentPage no longer relies on route matching, but it still treated any non-null progress value as content. That made the header logic vulnerable to showing content-only UI for non-content states such as serialized "0.00" progress.

• Site shell logic

  • Extract non-content progress states into a named constant
  • Use Array.includes to make the content/non-content decision explicit and easier to extend
  • Treat both null and "0.00" as non-content values

• Regression coverage

  • Add focused functional coverage for the layout contract on a non-content page
  • Rename the test to reflect the specific behavior under test

const NON_CONTENT_PERCENT_COMPLETE_VALUES = [null, "0.00"];

const isContentPage = computed(
    () => !NON_CONTENT_PERCENT_COMPLETE_VALUES.includes(percentComplete.value)
);

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• api.hcaptcha.com
  • Triggering command: /home/REDACTED/work/EssentialCSharp.Web/EssentialCSharp.Web/EssentialCSharp.Web.Tests/bin/Release/net10.0/EssentialCSharp.Web.Tests /home/REDACTED/work/EssentialCSharp.Web/EssentialCSharp.Web/EssentialCSharp.Web.Tests/bin/Release/net10.0/EssentialCSharp.Web.Tests --server dotnettestcli --dotnet-test-pipe /tmp/4acd2462732c41a891075494fa2abae7 (dns block)
• api.pwnedpasswords.com
  • Triggering command: /home/REDACTED/work/EssentialCSharp.Web/EssentialCSharp.Web/EssentialCSharp.Web.Tests/bin/Release/net10.0/EssentialCSharp.Web.Tests /home/REDACTED/work/EssentialCSharp.Web/EssentialCSharp.Web/EssentialCSharp.Web.Tests/bin/Release/net10.0/EssentialCSharp.Web.Tests --server dotnettestcli --dotnet-test-pipe /tmp/4acd2462732c41a891075494fa2abae7 (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)