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>

routers/web/org/projects.go

@@ -117,7 +117,7 @@ func Projects(ctx *context.Context) {
 
 func canWriteProjects(ctx *context.Context) bool {
 	if ctx.ContextUser.IsOrganization() {
-		return ctx.Org.CanWriteUnit(ctx, unit.TypeProjects)
+		return ctx.Org.CanWriteAnyRepoUnit(ctx, unit.TypeProjects)
 	}
 	return ctx.Doer != nil && ctx.ContextUser.ID == ctx.Doer.ID
 }