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.

src/data/AdminUserRepository.ts

@@ -0,0 +1,32 @@
+/** A user's role — mirrors `profiles.role`'s check constraint. Defined here
+ *  (data layer) rather than in state/authStore.ts so both that store and
+ *  this repository share one definition without state importing from data
+ *  in the wrong direction. */
+export type UserRole = 'regular' | 'admin' | 'super_admin'
+
+export interface AdminUserSummary {
+  id: string
+  username: string
+  email: string
+  role: UserRole
+  /** Set (a future timestamp) while banned; undefined otherwise. */
+  bannedUntil?: string
+  createdAt: string
+}
+
+/** Storage abstraction for Super-Admin user management (organized-ideas.md
+ *  §6's "CRUD user accounts"). Listing and role changes are plain
+ *  RLS/privileged-function reads and writes; ban/unban/delete go through
+ *  the admin-user-action Edge Function since those specifically need
+ *  Supabase Auth's Admin API — see that function's own header comment for
+ *  why this can't just be another SQL function like the rest. */
+export interface AdminUserRepository {
+  listUsers(): Promise<AdminUserSummary[]>
+  updateRole(userId: string, role: UserRole): Promise<void>
+  /** Reversible — blocks login without touching the account's data. */
+  banUser(userId: string): Promise<void>
+  unbanUser(userId: string): Promise<void>
+  /** Irreversible — cascades to the user's profile, diagrams, and owned
+   *  private catalog entries via their existing foreign keys. */
+  deleteUser(userId: string): Promise<void>
+}