P0 security batch: true global admin, quota gates on all spending paths, default quota for quota-less users, fix-review author trust + docker/owner attribution, GitHub App setup issuer binding, real cancel kill, wider shell env exclusion

- CODEX_GLOBAL_ADMINS replaces maintainer-derived global admin;
  admin endpoints (quotas, sweep, backup, push dispatch) fail-closed
  403 when unset, with audit on allow and deny.
- continue/followups/messages/retry check both caller and original
  creator quotas (USD + unpriced token cap), 402 on either overrun.
- Quota-less users now get the #86 default quota instead of unlimited;
  init_db backfills and OAuth create/bind/existing-login branches
  INSERT OR IGNORE a default row; explicit NULL row stays unlimited.
  user_quotas added to migration tables.
- /fix-review: untrusted authors rejected before dedup claim, no task;
  trusted tasks force executor=docker, created_by=project owner, owner
  quota gate, prompt is a fixed template plus a 2000-char excerpt.
- GitHub App setup state only issued by global admins, state rows bind
  issued_by (ALTER-compatible for old DBs), callback rejects issuers
  no longer in the admin list without consuming the state.
- Cancel: popen poll checks DB status every second, Docker path runs a
  cancel watchdog that kills by container name, write-back is CAS-guarded
  so late results never overwrite a new status.
- SHELL_ENV_EXCLUDE adds *_TOKEN, *_AUTH*, *_CREDENTIAL*, *API_KEY*;
  comment states the residual risk: same-UID /proc environ remains
  readable, true isolation needs UID separation or hidepid.
- Tests: new cloud/tests/test_p0_security.py (17 cases); old tests
  updated to the new semantics (admin env, default quota, trusted
  fix-review author) without weakening any gate.

cloud/migrations.py

@@ -39,6 +39,10 @@ MIGRATION_TABLES = (
     "oauth_states",
     "slack_users",
     "push_subscriptions",
+    # P0 安全批：配额行必须随库迁移，否则迁后用户变回无行
+    # （本批后无行按默认额度处理，不再是无限额，但显式
+    # 管理员额度仍需原样迁过去，不能丢）。
+    "user_quotas",
 )
 
 _SKIP_TABLES = frozenset({"kb_fts", "sqlite_sequence"})