test: validate $psake.build_success in per-file BeforeDiscovery bootstrap

[tablackburn]

Gap

The per-file BeforeDiscovery bootstrap in unit-test files calls Invoke-psake -TaskList 'Build' and proceeds straight to setting $Env:BHBuildOutput / Import-Module, without checking $psake.build_success.

If the Build task fails, the failure is swallowed and the next steps surface as a confusing path-not-found / import error rather than the actual build failure.

BeforeDiscovery {
    if ($null -eq $Env:BHBuildOutput) {
        $invokePsakeParameters = @{
            TaskList  = 'Build'
            BuildFile = $buildFilePath
        }
        Invoke-psake @invokePsakeParameters
        # <-- missing: if (-not $psake.build_success) { throw ... }
    }
    ...
}

Scope

Same gap in all 4 repos using this convention:

• tablackburn/PowerShellModuleTemplate (canonical)
• tablackburn/JsmOperations
• tablackburn/YouTubeMusicPS (post-PR-refactor(build): drop $_ prefix from helper variable names #20)
• tablackburn/SrrDBAutomationToolkit (post-PR-Add template-level CHANGELOG.md (CalVer) #15)

Fixing in the template propagates to derived repos on their next sync.

Fix sketch

In tests/Unit/Public/Get-{{Prefix}}Example.tests.ps1 and tests/Unit/Private/*.tests.ps1, after the Invoke-psake call:

Invoke-psake @invokePsakeParameters
if (-not $psake.build_success) {
    throw "Build task failed; cannot Import-Module the staged manifest. See psake output above."
}

Surfaced by

Copilot review on tablackburn/SrrDBAutomationToolkit PR #15 (responded as won't-fix in that PR — the right place is here so all derived repos inherit it).