enhance: inherit team access for all units (#38938)

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>

services/git/commit.go

@@ -41,7 +41,7 @@ func ParseCommitsWithSignature(ctx context.Context, repo *repo_model.Repository,
 		}
 
 		isOwnerMemberCollaborator := func(user *user_model.User) (bool, error) {
-			return repo_model.IsOwnerMemberCollaborator(ctx, repo, user.ID)
+			return repo_model.HasAccessToRepoCodeUnit(ctx, repo, user.ID)
 		}
 
 		_ = asymkey_model.CalculateTrustStatus(signCommit.Verification, repoTrustModel, isOwnerMemberCollaborator, &keyMap)