how do i sort recursive queries in sql server?

Build varchar sort key recursively and sort descending with a trick so that shorter values are considered greater.

WITH sorted AS
(
    SELECT 
        right(cast (1000000 + (select coalesce(max(t2.id),t.id) from tree_table t2 where t2.parent_id = t.id )as varchar(max)),6) AS [sort_key],
        t.id,
        t.parent_id,
        t.name
    FROM
        tree_table t
),
rcte AS (
    SELECT * 
    FROM  sorted t
    WHERE 
        t.parent_id = 0
    UNION ALL
    SELECT 
        r.sort_key + t.sort_key,
        t.id,
        t.parent_id,
        t.name
    FROM
        sorted t
    JOIN
        rcte r ON r.id = t.parent_id
)
SELECT * 
FROM rcte
ORDER BY 
   stuff(replicate(cast ('9' as varchar(max)), (select max(len(r2.sort_key)) from rcte r2)),1,len(sort_key), sort_key) 
DESC;

I assumed id <1000000 for simplicity, you can easily adjust it to any big value with bigint arithmetic.

Output :

sort_key                    id  parent_id   name
000019                      16  0   4Title
000019000020                17  16    ㄴRE 4Title 1-1
000019000020000020          20  17      ㄴRE 4Title 1-1-1
000019000019                19  16    ㄴRE 4Title 1-2
000014                      1   0   1Title
000014000015                6   1     ㄴRE 1Title 1-3
000014000015000018          15  6       ㄴRE 3Title 1-3-1
000014000015000018000018    18  15        ㄴRE 3Title 1-3-1-1
000014000014                14  1     ㄴRE 1Title 1-4
000014000012                4   1     ㄴRE 1Title 1-1
000014000012000012          12  4       ㄴRE 1Title 1-1-3
000014000012000011          11  4       ㄴRE 1Title 1-1-2
000014000012000010          10  4       ㄴRE 1Title 1-1-1
000014000005                5   1     ㄴRE 1Title 1-2
000013                      3   0   3Title
000013000013                13  3     ㄴRE 3Title 1-1
000009                      2   0   2Title
000009000009                9   2     ㄴRE 2Title 1-3
000009000008                8   2     ㄴRE 2Title 1-2
000009000007                7   2     ㄴRE 2Title 1-1