ET-013: deployer writes 14-deploy-log.md and merges deploy artifacts into
main via a separate PR, so the log lands in origin/main, not the feature
branch worktree that check_deploy_status reads via _repo_path(repo, branch).
Result: every successful deploy was falsely failed (Deploy log not found)
and rolled back deploy->development.
Fix: when the log is absent in the worktree, fall back to reading it from
origin/main on the shared clone (git fetch origin main + git show
origin/main:docs/work-items/<WI>/14-deploy-log.md). Lookup order:
worktree -> origin/main -> not found. Fetch/show failures degrade to
not found (never raise). Does not touch the merge-gate in gitea.py.
Tests: origin/main SUCCESS->PASS (ET-013 case), origin/main FAILED->FAILED,
absent everywhere->not found, fetch failure->degrades no exception,
worktree log short-circuits main lookup.
