After creating a working checkout, if find_local_repos() finds a local
clone or fork of the same project, rename 'origin' (bare cache) to
'upstream' and add a new 'origin' pointing at the local repo. Mirrors
the standard fork workflow: fetch from upstream, push to origin (local
repo), then push to the shared remote and open a PR. If no local repo
is found, origin stays as the bare cache (read-only). Idempotent.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Implements ifcurl-5oo. get_checkout() ensures the bare cache is current via
fetch_ifc(), then clones it locally to <cache_dir>/checkout/ (no network),
and places it at the resolved commit as a detached HEAD — forcing branch
creation before any commit. Viewer artefact patterns (*.ifcview, *.rdbview,
etc.) are appended to .git/info/exclude so they are locally ignored without
touching the repo's own .gitignore. When a newer commit is requested, the
checkout fetches from origin (the local bare cache) using the default refspec
to avoid git's "refusing to fetch into checked-out branch" error. Unblocks
the JSON-RPC connector (ifcurl-242).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
