sx-gitea Phase 2: access — acl-backed permissions, collaborators, teams, auth-gated routes (TDD, 194/194)

lib/gitea/access.sx: repo role groups (admin>write>read) as acl facts
saturated by the datalog engine; user-owner => admin; collaborators
(per-repo role, upsert); org teams (one role, 'all' or scoped repo
list); org-admin?; visible-repos; create-allowed?; bearer tokens in kv.
Facts derived from forge state, acl db cached in the forge handle and
rebuilt only when facts change.

lib/gitea/web.sx: every repo route now requires read (404 hides private
repos); repo create needs owner/org-admin, delete + collaborator API
need admin (401 no credentials / 403 not allowed); index + /api/repos
list only visible repos; PUT/DELETE collab endpoints.

tests/access.sx (103) + repo suite updated for gating (91). Fixed a
web.sx corruption from the known sx_find_all/sx_replace_node path
mismatch by rewriting via sx_write_file; suite timeout 300->600s.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

lib/gitea/scoreboard.md

@@ -5,4 +5,5 @@ _Generated by `lib/gitea/conformance.sh`_
 | Suite | Pass | Fail | Total |
 |-------|-----:|-----:|------:|
 | repo | 91 | 0 | 91 |
-| **Total** | **91** | **0** | **91** |
+| access | 103 | 0 | 103 |
+| **Total** | **194** | **0** | **194** |