Use the system temp directory for temporary font downloads

[MariusStorhaug]

Context and request

Install-GoogleFont creates its per-invocation download directory under $HOME:

$guid = (New-Guid).Guid
$tempPath = Join-Path -Path $HOME -ChildPath "GoogleFonts-$guid"

When an installation fails or is interrupted before the clean block runs, downloaded artifacts remain in the user's home directory. Those directories are not managed by normal operating-system temporary-file cleanup.

Desired outcome

Create temporary download directories under the platform's system-designated temporary path, while retaining the existing GUID-based uniqueness and cleanup behavior.

Acceptance criteria

• Install-GoogleFont bases its temporary directory on [System.IO.Path]::GetTempPath() rather than $HOME.
• The per-invocation GUID naming scheme remains collision-safe.
• The clean block continues to remove the temporary directory after a normal or terminating invocation.
• Successful installation behavior is unchanged on Windows, Linux, and macOS.

Related

• Use system temp directory for temporary font downloads instead of $HOME NerdFonts#63 documented the same defect in the sibling module; its implementation was delivered by ⚙️ [Maintenance]: CI and documentation builds use Process-PSModule v6.1.19 NerdFonts#91.
• Install-GoogleFont: follow-ups from PR #210 review (-Force vs cache, -WhatIf, retries, cache path, tests) #211 tracks separate cache and download robustness follow-ups.