Add Roles & Admin/Super-Admin interface

Per organized-ideas.md §6: role assignment, account ban/unban/delete, and
direct Admin/Super-Admin CRUD of public catalog entries outside the
submission workflow.

Backend:
- list_users_for_admin(): Super-Admin-gated SECURITY DEFINER function
  joining profiles + auth.users (username, email, role, banned_until) —
  auth.users isn't exposed through PostgREST, so this is the only way to
  list accounts at all.
- New Edge Function admin-user-action (ban/unban/delete), using
  @supabase/server's `auth: 'user'` mode to verify the caller's JWT, then
  Supabase Auth's Admin API for the actual mutation. This is deliberately
  an Edge Function rather than a Postgres function like everything else in
  this codebase: touching auth.users needs the Admin API, the stable
  documented interface, not a direct write to a schema Supabase manages
  internally. Self-action guard; verify_jwt = true at the gateway on top of
  the function's own JWT verification.
- 5 new pgTAP tests (43/43 total) for list_users_for_admin (Super-Admin-only,
  even regular Admins get 42501).
- CatalogRepository gains admin* methods (direct edit of a public port/cable/
  device entry, plus adminUnpublish which flips is_public rather than
  deleting) — the update methods were already ownership-agnostic (RLS's
  is_admin() clause is what actually permits it), so these are thin aliases,
  not duplicated logic.

Frontend:
- authStore/AdminUserRepository: minimal role plumbing, shared UserRole type.
- adminUserStore + AdminUsersModal: list/role-dropdown/ban/unban/delete,
  gated to Super Admin only via a new "Manage Users" TopBar button.
- PortTypeManager/CableTypeManager/DevicePalette: built-in entries now show
  direct "Edit"/"Unpublish" for Admins (regular Admin included, per §6's
  capability table — not Super-Admin-exclusive) instead of "Suggest edit";
  unpublish reuses the review-queue's impact-check RPC before confirming.
- DeviceTemplateEditor gains an `adminMode` save path alongside its existing
  submissionMode/resubmitId ones.

Verified: tsc -b and oxlint clean; supabase db reset + 43/43 pgTAP tests
pass; confirmed both new privileged endpoints (the SQL function and the
Edge Function) actually work through the real REST API via live curl
calls — signup, email confirm, role promotion, ban/unban/delete round
trips, self-action guard, non-super-admin rejection, and verify_jwt=true
compatibility all exercised directly, not just asserted.

supabase/migrations/20260912000000_admin_user_management.sql

@@ -0,0 +1,30 @@
+-- Super-Admin user management (organized-ideas.md §6): "CRUD user accounts"
+-- starts with being able to see them at all. auth.users isn't exposed
+-- through PostgREST (by design — Supabase doesn't expose the `auth` schema
+-- to the API), so this read-only, Super-Admin-gated function is the only
+-- way the app can list users alongside their profile/ban status. The
+-- mutations themselves (ban/unban/delete) go through a new Edge Function
+-- instead of a SQL function here — those specifically need Supabase Auth's
+-- Admin API (auth.admin.updateUserById/deleteUser), the stable, documented
+-- interface for touching auth.users, rather than writing to that schema's
+-- tables directly (undocumented, not guaranteed stable across upgrades).
+
+create or replace function public.list_users_for_admin()
+returns table(id uuid, username text, email text, role text, banned_until timestamptz, created_at timestamptz)
+language plpgsql
+stable
+security definer
+set search_path = public
+as $$
+begin
+  if not public.is_super_admin() then
+    raise exception 'insufficient_privilege' using errcode = '42501';
+  end if;
+
+  return query
+    select p.id, p.username, u.email::text, p.role, u.banned_until, p.created_at
+    from public.profiles p
+    join auth.users u on u.id = p.id
+    order by p.created_at desc;
+end;
+$$;