[tedchamb]

Problem

The dotfiles installer runs with set -e and invokes the PowerShell-based
logfmtpp downloader before VS Code extension installation. On machines without
pwsh, that step fails and prevents the remaining setup from running.

Changes

• Check whether pwsh is available before setting up the PowerShell profile and
  installing logfmtpp.
• Print a clear skip message when PowerShell is unavailable, then continue with
  VS Code extension setup.
• Preserve the existing installation order and failure propagation when
  PowerShell is available.
• Document how to enable the skipped steps later.

Validation

• bash -n install.sh
• shellcheck -e SC1091 install.sh (checks the changed installer without following
  sourced scripts)
• git diff --check
• Isolated installer fixtures verified:
  • Missing pwsh: both dependent steps are skipped and VS Code setup runs.
  • Available pwsh: all steps run in their existing order.
  • Both configurations behave consistently on repeat runs.
  • A real logfmtpp installation failure still stops the installer when pwsh
    is available.

The full installer was not rerun against the current machine; the fixtures
stubbed installation steps and used a temporary home directory.