fix(release-script): stage the showcase assets the cut regenerates

git applies an :(exclude) pathspec to the whole `git add` invocation rather than
to the pathspecs standing beside it. The generated-page globs carry
:(exclude)web/showcase, so that a file planted under the showcase cannot be
mistaken for a card page, and they were concatenated into the same add as the
showcase assets themselves - which the exclusion then cancelled. Measured on this
tree: the release commit's own pathspec list stages 0 paths under web/showcase,
and the same list without the exclusion stages 133.

So the v2.4.1 cut committed none of the 133 showcase files its own Step 4c had
just rewritten, and left them as working-tree churn under a tag that was supposed
to carry them - the site on main would have served the previous release's renders,
including the barcodes this release redraws.

The page globs now stage through an add of their own, where the exclusion reaches
only the globs it belongs to.

The CI step that owns these pathspecs lifts Get-GeneratedPagePathspecs by AST and
runs it alone, where the exclusion behaves correctly, so it passed throughout: it
tests the function, not the invocation the function's result ends up in.

Author: DemchaAV

scripts/cut-release.ps1

@@ -1892,8 +1892,13 @@ try {
     )
     # The documentation page and the document pages name the release too — in their guide links
     # and their coordinates — so they ride with the page and the data above, a page per card
-    # included, and any page the rebuild deleted.
-    $commitFiles += @(Get-GeneratedPagePathspecs)
+    # included, and any page the rebuild deleted. They stage through an `add` of their own,
+    # because their list carries :(exclude)web/showcase and git applies an exclude to the
+    # WHOLE invocation rather than to the pathspecs beside it. Listed in one `add` with the
+    # showcase assets below, the exclude cancelled them: the first v2.4.1 cut committed none
+    # of the 133 showcase files its own regeneration had just rewritten, and left them as
+    # working-tree churn under a tag that was supposed to carry them.
+    $pagePathspecs = @(Get-GeneratedPagePathspecs)
     # qa + coverage exist only in the 2.0 aggregator layout; add them to the commit
     # only when present so the script stays layout-agnostic (the 1.x single-artifact
     # tree has neither) — mirroring Update-PomVersion's skip-if-absent guard. On a 2.0
@@ -1961,9 +1966,15 @@ try {
     }
     if ($DryRun) {
         Write-Host "    [DRY RUN] git add $($commitFiles -join ' ')" -ForegroundColor Yellow
+        if ($pagePathspecs.Count) {
+            Write-Host "    [DRY RUN] git add $($pagePathspecs -join ' ')" -ForegroundColor Yellow
+        }
         Write-Host "    [DRY RUN] git commit -m `"$commitMsg`"" -ForegroundColor Yellow
     } else {
         Invoke-Git add @commitFiles
+        if ($pagePathspecs.Count) {
+            Invoke-Git add @pagePathspecs
+        }
         Invoke-Git commit -m $commitMsg
         Note "commit: $commitMsg"
     }