feat(workspace): WorktreeService with acquire/release state machine

internal/workspace/sqlc/worktrees.sql.go

@@ -111,6 +111,28 @@ func (q *Queries) GetWorktreeByID(ctx context.Context, id pgtype.UUID) (Workspac
 	return i, err
 }
 
+const getWorktreeByIDForUpdate = `-- name: GetWorktreeByIDForUpdate :one
+SELECT id, workspace_id, branch, path, status, active_holder, acquired_at, last_used_at, created_at FROM workspace_worktrees WHERE id = $1
+FOR UPDATE
+`
+
+func (q *Queries) GetWorktreeByIDForUpdate(ctx context.Context, id pgtype.UUID) (WorkspaceWorktree, error) {
+	row := q.db.QueryRow(ctx, getWorktreeByIDForUpdate, id)
+	var i WorkspaceWorktree
+	err := row.Scan(
+		&i.ID,
+		&i.WorkspaceID,
+		&i.Branch,
+		&i.Path,
+		&i.Status,
+		&i.ActiveHolder,
+		&i.AcquiredAt,
+		&i.LastUsedAt,
+		&i.CreatedAt,
+	)
+	return i, err
+}
+
 const listWorktreesByWorkspace = `-- name: ListWorktreesByWorkspace :many
 SELECT id, workspace_id, branch, path, status, active_holder, acquired_at, last_used_at, created_at FROM workspace_worktrees
 WHERE workspace_id = $1