Admin and write team authorize now grant that mode on every unit,
including units added later, instead of only rows present in
`team_unit`. Granular teams keep `authorize=none` and explicit unit
rows.
Closes the `TEAM-UNIT-PERMISSION` design gap from
https://github.com/go-gitea/gitea/pull/34128.
Maybe also fix#15962 (actually maybe it had been fixed before, the root
cause is out-of-sync "access" table)
## Screenshots
only writing selected:
<img width="1399" height="1007" alt="image"
src="https://github.com/user-attachments/assets/1d1b4c49-a59a-47b6-998f-0464a067395b"
/>
_Created with the help of AI_
---------
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>