Installer: drop redundant -WindowStyle Hidden from the Windows launcher VBS (#6284)

* Installer: drop redundant -WindowStyle Hidden from the Windows launcher VBS

The desktop / Start Menu shortcut launches Studio through a generated
launch-studio.vbs that runs:

  shell.Run "powershell ... -WindowStyle Hidden -File launch-studio.ps1", 0, False

The second argument to shell.Run is intWindowStyle 0 (hidden), so WScript
already launches the child windowless. The child -WindowStyle Hidden is
therefore redundant: dropping it keeps the launcher hidden and behaviour
identical, while removing the WScript-spawns-hidden-ExecutionPolicy-Bypass
PowerShell token combination that antivirus heuristics weight. That shape was
reported as a Kaspersky HEUR:Trojan.VBS.Agent false positive during install.

Adds tests/studio/install/test_launch_studio_launcher.py to stop the flag from
being reintroduced and to assert the launcher stays windowless via
shell.Run(cmd, 0, False).

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Co-authored-by: Daniel Han <michaelhan2050@gmail.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

install.ps1

@@ -799,9 +799,11 @@ exit 0
             # even when install.ps1 is executed from PowerShell 7.
             $utf8Bom = New-Object System.Text.UTF8Encoding($true)
             [System.IO.File]::WriteAllText($launcherPs1, $launcherContent, $utf8Bom)
+            # shell.Run(cmd, 0, ...) already hides the window, so -WindowStyle Hidden
+            # is redundant; omitting it trims an AV-heuristic token (Kaspersky FP).
             $vbsContent = @"
 Set shell = CreateObject("WScript.Shell")
-cmd = "powershell -NoProfile -ExecutionPolicy Bypass -WindowStyle Hidden -File ""$launcherPs1"""
+cmd = "powershell -NoProfile -ExecutionPolicy Bypass -File ""$launcherPs1"""
 shell.Run cmd, 0, False
 "@
             # WSH handles UTF-16LE reliably for .vbs files with non-ASCII paths.

tests/studio/install/test_launch_studio_launcher.py

@@ -0,0 +1,50 @@
+"""Guard install.ps1's launch-studio.vbs against re-introducing the AV-heuristic
+shape: a WScript .vbs spawning a hidden, ExecutionPolicy-Bypass PowerShell."""
+
+import re
+from pathlib import Path
+
+import pytest
+
+REPO_ROOT = Path(__file__).resolve().parents[3]
+INSTALL_PS1 = REPO_ROOT / "install.ps1"
+
+
+def _vbs_block() -> str:
+    text = INSTALL_PS1.read_text(encoding = "utf-8")
+    m = re.search(r'\$vbsContent\s*=\s*@"\r?\n(.*?)\r?\n"@', text, re.S)
+    assert m, "could not locate the $vbsContent here-string in install.ps1"
+    return m.group(1)
+
+
+def test_install_ps1_present():
+    assert INSTALL_PS1.is_file(), f"missing {INSTALL_PS1}"
+
+
+def test_vbs_does_not_pass_windowstyle_hidden():
+    vbs = _vbs_block()
+    assert "-WindowStyle Hidden" not in vbs, (
+        "launch-studio.vbs must not pass -WindowStyle Hidden to PowerShell: the "
+        "window is already hidden by shell.Run(cmd, 0, False); the redundant flag "
+        "only adds the hidden-PowerShell token that AV heuristics flag."
+    )
+
+
+def test_vbs_stays_windowless_via_shell_run():
+    vbs = _vbs_block()
+    assert re.search(r"shell\.Run\s+cmd\s*,\s*0\s*,\s*False", vbs), (
+        "launcher must remain windowless via shell.Run(cmd, 0, False) "
+        "(intWindowStyle 0 = hidden)."
+    )
+
+
+def test_vbs_keeps_bypass_and_file_invocation():
+    # Bypass lets the unsigned local .ps1 run under the default Restricted policy.
+    vbs = _vbs_block()
+    assert "-ExecutionPolicy Bypass" in vbs
+    assert "-File" in vbs
+    assert "powershell" in vbs
+
+
+if __name__ == "__main__":
+    raise SystemExit(pytest.main([__file__, "-v"]))