fix(powershell): stop Out-Null swallowing setup-tasks AVAILABLE_DOCS lines

Test-FileExists / Test-DirHasFiles report their line with Write-Output and
ALSO return $true/$false -- both on the Success stream. setup-tasks.ps1's
text-mode branch piped each call to `| Out-Null` to discard the boolean,
which discarded the report line with it, so AVAILABLE_DOCS: printed with
nothing under it:

  BEFORE (measured, powershell.exe -NoProfile -File ...):
    FEATURE_DIR:...\specs\001-my-feature
    TASKS_TEMPLATE:...\tasks-template.md
    AVAILABLE_DOCS:
    (3 lines)

  AFTER:
    FEATURE_DIR:...\specs\001-my-feature
    TASKS_TEMPLATE:...\tasks-template.md
    AVAILABLE_DOCS:
      [OK] research.md
      [FAIL] data-model.md
      [FAIL] contracts/
      [FAIL] quickstart.md
    (7 lines)

The bash twin (scripts/bash/setup-tasks.sh) lists every document under that
header, so the PowerShell variant silently returned less information for
the same inputs.

Same bug, same fix shape (filter out only the boolean with Where-Object)
as the sibling that was just fixed in check-prerequisites.ps1 (upstream
commit 2b36f0c, PR #3891) -- this is the unfixed twin call site sharing
the same Test-FileExists/Test-DirHasFiles helpers in common.ps1.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Author: Noor-ul-ain001

scripts/powershell/setup-tasks.ps1

@@ -81,8 +81,13 @@ if ($Json) {
     Write-Output "FEATURE_DIR: $($paths.FEATURE_DIR)"
     Write-Output "TASKS_TEMPLATE: $(if ($tasksTemplate) { $tasksTemplate } else { 'not found' })"
     Write-Output "AVAILABLE_DOCS:"
-    Test-FileExists -Path $paths.RESEARCH -Description 'research.md' | Out-Null
-    Test-FileExists -Path $paths.DATA_MODEL -Description 'data-model.md' | Out-Null
-    Test-DirHasFiles -Path $paths.CONTRACTS_DIR -Description 'contracts/' | Out-Null
-    Test-FileExists -Path $paths.QUICKSTART -Description 'quickstart.md' | Out-Null
+    # These helpers report their line with Write-Output and ALSO return a
+    # bool, both on the Success stream, so 'Out-Null' discarded the report
+    # line along with the return value and left AVAILABLE_DOCS empty. Drop
+    # only the boolean so the per-document lines reach stdout like the
+    # bash and Python twins.
+    Test-FileExists -Path $paths.RESEARCH -Description 'research.md' | Where-Object { $_ -isnot [bool] }
+    Test-FileExists -Path $paths.DATA_MODEL -Description 'data-model.md' | Where-Object { $_ -isnot [bool] }
+    Test-DirHasFiles -Path $paths.CONTRACTS_DIR -Description 'contracts/' | Where-Object { $_ -isnot [bool] }
+    Test-FileExists -Path $paths.QUICKSTART -Description 'quickstart.md' | Where-Object { $_ -isnot [bool] }
 }

tests/test_setup_tasks.py

@@ -796,6 +796,39 @@ def test_setup_tasks_ps_missing_template_errors(tasks_repo: Path) -> None:
     assert "tasks-template" in result.stderr.lower() or "tasks-template" in result.stdout.lower()
 
 
+@pytest.mark.skipif(not (HAS_PWSH or _WINDOWS_POWERSHELL), reason="no PowerShell available")
+def test_setup_tasks_ps_text_output_lists_available_docs(tasks_repo: Path) -> None:
+    """Text mode must print a status line per document, like the bash/Python twins.
+
+    `Test-FileExists` / `Test-DirHasFiles` report their line with `Write-Output`
+    and ALSO `return $true/$false`, both on the Success stream. Piping the whole
+    call to `| Out-Null` discarded the boolean AND the report line, so
+    `AVAILABLE_DOCS:` was emitted with nothing under it.
+    """
+    feat = _minimal_feature(tasks_repo)
+    (feat / "research.md").write_text("# research\n", encoding="utf-8")
+
+    script = tasks_repo / ".specify" / "scripts" / "powershell" / "setup-tasks.ps1"
+    exe = "pwsh" if HAS_PWSH else _WINDOWS_POWERSHELL
+
+    result = subprocess.run(
+        [exe, "-NoProfile", "-File", str(script)],
+        cwd=tasks_repo,
+        capture_output=True,
+        text=True,
+        check=False,
+        env=_clean_env(),
+    )
+
+    assert result.returncode == 0, result.stderr + result.stdout
+    assert "AVAILABLE_DOCS:" in result.stdout
+    for doc in ("research.md", "data-model.md", "contracts/", "quickstart.md"):
+        assert doc in result.stdout, (doc, result.stdout)
+    normalized = result.stdout.replace("\r\n", "\n")
+    assert "[OK] research.md" in normalized, normalized
+    assert "[FAIL] data-model.md" in normalized, normalized
+
+
 @pytest.mark.skipif(not (HAS_PWSH or _WINDOWS_POWERSHELL), reason="no PowerShell available")
 def test_powershell_command_hint_normalizes_mixed_separators(
     tasks_repo: Path,