`gh copilot` resolves wrong repository owner - uses local username instead of git remote

[RuniThomsen]

Description

gh copilot resolves the repository owner incorrectly when the local filesystem username differs from the GitHub organization that owns the repo.

Expected behavior

gh copilot should resolve the repo owner from git remote get-url origin, matching how gh repo view works.

Actual behavior

gh copilot uses the local filesystem username (runithomsen) as the repo owner instead of the actual GitHub organization (runi-finance) from the git remote.

This causes all GitHub MCP tool calls within Copilot agents to fail with 404:

✘ github-mcp-server-issue_read
   MCP error 0: failed to get issue: GET
   https://api.github.com/repos/runithomsen/governance/issues/189: 404 Not Found []

Steps to reproduce

1. Clone an org repo: git clone https://github.com/runi-finance/governance.git
2. Verify remote: git remote get-url origin → https://github.com/runi-finance/governance.git
3. Verify gh resolves correctly: gh repo view --json owner → {"owner":{"login":"runi-finance"}}
4. Run copilot with an agent that uses GitHub MCP tools
5. Observe that MCP calls target runithomsen/governance instead of runi-finance/governance

Environment

• gh copilot version: 1.2.0 (2025-10-30)
• gh version: (latest)
• OS: macOS (Darwin 25.2.0)
• Git remote: https://github.com/runi-finance/governance.git

Impact

All GitHub MCP server tool calls (issue reads, PR reads, code search scoped to repo) fail with 404 when the repo is owned by an organization different from the local username. This effectively breaks any Copilot agent that needs to interact with GitHub issues or PRs in org-owned repos.