* feat(dep_ensure): complete Windows bootstrap — dep_ensure + install.ps1 + detection
dep_ensure.py gains Windows awareness: PowerShell invocation, platform-
specific browser detection, (path, shell) tuple returns.
install.ps1 gains -Ensure/-PostInstall modes using npm -g --prefix
(aligned with install.sh) and agent-browser install for Chromium.
browser_tool.py gains node/ in candidate dirs for Windows .cmd shims.
Both install scripts bundled in pip wheel.
Tracking: #27826
* fix(install.ps1): add --ignore-scripts to npm install for camofox
@askjo/camofox-browser has a dependency (impit) whose postinstall
script runs `npx only-allow pnpm`, which fails under npm. Adding
--ignore-scripts avoids the spurious failure without affecting
functionality.
Tracking: #27826
* fix: remove duplicate install scripts from git
CI already copies scripts/install.{sh,ps1} into hermes_cli/scripts/
during wheel build. No need to commit copies — .gitignore keeps them
out, _find_install_script() falls back to scripts/ for git-clone users.
Tracking: #27826
* fix: address review — remove env_extra, fix ps1 error handling
- Remove unused env_extra parameter from ensure_dependency()
- Invoke-EnsureMode node case now uses Test-Node consistently
- Install-AgentBrowser uses throw instead of exit 1
