hermes - 💡(How to fix) Fix [Desktop] Tools & Keys → GitHub shows 'Internal server error' when saving/removing classic PAT (ghp_*) [1 pull requests]

Problem

The Hermes Desktop Tools & Keys → GitHub settings page cannot save or remove a GitHub token, and shows a generic "Internal server error" when trying to do so.

Steps to reproduce

1. Open Hermes Desktop → Settings → Tools & Keys → GitHub
2. Paste a classic GitHub Personal Access Token (ghp_...) into the token field
3. Click save

Actual result: Failed to add GITHUB_TOKEN / Internal server error Expected result: Token accepted and saved, or a clear error message explaining why it was rejected.

Root cause

The Desktop settings backend validates the token against the Copilot API, which only accepts fine-grained PATs (github_pat_*) or OAuth tokens (gho_*). Classic PATs (ghp_*) are rejected by the Copilot API but are still valid for the GitHub REST API (issues, PRs, forks) and Skills Hub rate limiting.

The error is caught without a human-readable message and surfaces as a generic "Internal server error" in the UI.

Impact

• Users who manually add GITHUB_TOKEN to their ~/.hermes/.env file (the recommended method) see the token detected (green indicator light in the UI) but cannot remove or replace it through the UI
• Users trying to add a token through the UI for the first time get an unhelpful error with no guidance on what token type to use
• The UI should either accept classic PATs (validating against the REST API instead of Copilot) or clearly explain the token type requirement

Related

• #13988 — tracks Copilot auth rejecting classic PATs (validation layer)
• This issue is about the Desktop settings UI error handling specifically — even if Copilot rejects classic PATs, the UI should show a human-readable message instead of "Internal server error"

Suggested fix

The Desktop settings page should either:

1. Validate against the GitHub REST API (https://api.github.com/user) instead of the Copilot API — both token types work here
2. Or catch the Copilot rejection and display a meaningful message: "Classic personal access tokens (ghp_) are not supported. Use a fine-grained PAT (github_pat_) with Copilot Requests permission, or run gh auth login."