Add worktree support to SessionService via the hqt.git.worktree module:
- create_session(worktree_branch=...): creates the worktree before the row
(ServiceError → no row, no spawn); spawn/capture use the worktree path;
blank nickname defaults to the branch name.
- _session_path / _repo_path_for_worktree helpers route every harness-facing
path through the worktree when set, with a parent.parent repo fallback when
the project row is gone.
- attach_session rung 0: recreate a missing worktree from its branch, else
raise "delete the session".
- delete_session(remove_worktree=, force=): remove worktree before deleting
the row; removal failure keeps the row.
- worktree_state_for(session_id): None for plain/missing sessions, else the
module's WorktreeState.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
felixm
61f1a07ba7