Namespace-scoped workspace resolution prevents GITEA_AUTHOR_WORKTREE from
poisoning reviewer, merger, and reconciler purity checks. Each role uses
its own worktree env var with actionable binding-source errors and safe
reconnect guidance. Preserves #274/#475 author and control-checkout guards.
Share canonical workspace/repo-root resolution between gitea_get_runtime_context
and verify_preflight_purity so valid branches/ worktrees are not rejected when
the MCP process root differs from the stable control checkout. Fix relative
git-common-dir resolution and add regression tests.
Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
Merge prgs/master into feat/issue-274-branches-only-worktrees; keep both
already_landed_reconcile and author_mutation_worktree imports. Allow
branches/ worktrees when PROJECT_ROOT is the session worktree; align
commit-payload tests with branches-only guard (#274).
Add author_mutation_worktree assessment and integrate it into MCP
preflight so author mutations fail closed outside branches/ session
worktrees, with tests for control-checkout and branches-path cases.
Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>