Model the read/write split in the UI: read-only views, self-revoke and inherited-grant guards

todo.md

@@ -2,6 +2,11 @@
 
 ## Unfinnished work
 
+- [ ] The permission picker has no concurrency baseline, so two operators editing the same user/group silently discard each other's change (standard lost-update on a set-based form — and the natural "two of us are onboarding the new hire" workflow produces exactly it). Sketch: post the rendered set as a hidden baseline; if it no longer matches Keto, re-render with "this changed while you had the page open" rather than applying. Fits the existing "the form is the whole truth" model instead of fighting it. Raised by the product review 2026-08-05.
+- [ ] A grant whose plugin was uninstalled is invisible and unremovable in the GUI. `grantDiff` deliberately never revokes an undeclared name (so an unrelated save can't drop it), but nothing *shows* it either — so it can't be audited or cleaned, and reinstalling that plugin silently reactivates access nobody remembers granting. Sketch: a read-only "held, but no installed plugin offers this" list with a remove action. Raised by the product review 2026-08-05.
+- [ ] A plugin may gate a route on a permission it never declares — declaring stays optional on purpose (mandatory declaration would warn on the legitimate cross-plugin sharing case). The cost is a dead end: the picker is built from declarations only, so that route is ungrantable from the GUI with no boot error, no warning, and a permanent 403 as the operator's only clue. Sketch: a discovery *warning* (not an error) naming the gated-but-undeclared permission. Raised by the product review 2026-08-05.
+- [ ] Saving permissions gives no confirmation, and a partial failure is silent. `applyGrants` loops writes then deletes with no transaction, so a Keto error midway leaves a half-applied set behind the generic error page; and a *successful* save is indistinguishable from "nothing changed" (PRG back to the same page, checkboxes as the only feedback). The `alert alert-pos` pattern the recovery-code banner uses is already available. Raised by the product review 2026-08-05.
+- [ ] Add the read-only operator to README → Overview's personas. `users:read` now makes a support/helpdesk account possible for the first time, and it is a distinct persona from the three listed (end user, non-technical user, plugin author) — the one whose screens must render without write affordances. Writing it down makes read-only rendering a stated requirement rather than something the next reviewer rediscovers. Raised by the product review 2026-08-05.
 - [ ] The seeded admin@plainpages.local are assigned twice to the permission "admin", should only be one, right? (the "admin" permission name can be switched after previous todos have been done)
 - [ ] In Playwright tests, try different resolutions and sizes, from BIG desktop down to tiny phone.
 - [ ] Decide whether `e2e-tests/` should be typechecked. It is outside `tsconfig.include`, so the gate never checks the most logic-bearing file in it (`console-guard.ts`) — Playwright strips its types without checking them. Including it needs the DOM lib and `@playwright/test` present wherever `npm run typecheck` runs, which today is the `web` image that installs neither. Raised by review 2026-08-05.