fix(dev-config): Use skipExistingInit to prevent overwriting existing oh-my-posh config

[shunkin (shunkino)]

Fixes #53

Issue

In windows-dev-config/dev-config.winget, the config uses:

- type: OhMyPosh/Shell
  name: ohMyPoshProfileSet
  dependsOn:
    - OhMyPosh
  properties:
    states:
      - name: pwsh
        command: oh-my-posh init pwsh

When DSC is applied, it updates the existing oh-my-posh init line in $PROFILE to the declared command.

That means a custom line like:

oh-my-posh init pwsh --config "$HOME\.config\oh-my-posh\M365Princess.omp.json" | Invoke-Expression

gets rewritten to:

oh-my-posh init pwsh | Invoke-Expression

Why this is a problem

Many users customize their prompt via --config, and this is valid/manual user configuration. The rest of the profile remains untouched, but the oh-my-posh line is normalized and the custom theme/config is lost.

Fix

Thanks to the upstream improvement, oh-my-posh DSC module now have a feature to skip the update when there's existing configuration.

With this, we can simply fix the issue like this:

- type: OhMyPosh/Shell
  name: ohMyPoshProfileSet
  dependsOn:
    - OhMyPosh
  properties:
    states:
      - name: pwsh
        command: oh-my-posh init pwsh
        skipExistingInit: true