`/pr` does not recognize GitHub repositories that use SSH host aliases

Describe the bug

When using Copilot CLI's /pr command in a repository whose origin remote uses an SSH host alias (defined in ~/.ssh/config), the command fails with:

The /pr command requires a repository connected to GitHub (github.com or *.ghe.com remote).

For example, my remote is:

git@github-personal:nickcoffey/PySwap.git

where github-personal is an SSH alias that resolves to github.com and uses a specific SSH key for one of multiple GitHub accounts.

The repository is a valid GitHub repository, and GitHub CLI recognizes it correctly (gh repo view succeeds). This suggests /pr is validating the literal remote hostname instead of resolving SSH aliases or using Git/GitHub metadata to determine the repository.

Affected version

GitHub Copilot CLI 1.0.73.

Steps to reproduce the behavior

1. Configure an SSH host alias in ~/.ssh/config that resolves to github.com, for example:

   Host github-personal
       HostName github.com
       User git
       IdentityFile ~/.ssh/id_ed25519_personal
   

2. Clone or configure a GitHub repository using the SSH alias as the remote:

   git remote set-url origin git@github-personal:OWNER/REPO.git
   

3. Verify the repository is accessible:

   gh repo view # this should succeed 
   

4. Run the Copilot CLI /pr command from the repository.

Expected behavior

/pr should work with repositories that use SSH host aliases which ultimately resolve to github.com or GitHub Enterprise hosts.

Additional context

• Operating system: macOS
• CPU architecture: ARM
• Terminal emulator: Ghostty
• Shell: zsh

Start at the /pr command's repository validation and remote URL handling. Reproduce the failure with the github-personal SSH alias and compare it with the successful gh repo view check; done when /pr accepts aliases resolving to GitHub hosts while retaining normal GitHub Enterprise support.