remove the dead multi-user surface

Officer is single-user: the server owner is the only account, created once by
/auth/bootstrap. Everything that existed to serve additional users was
unreachable, so it is gone rather than left looking like it does something.

Accounts: drop the invite / resend-invite / delete / list-users routes and the
Users settings screen, the inert /auth/signup handler, and the account
verification chain it fed (verify, resend-verification, VerifyScreen, the
UserInvite + VerifyAdmin + VerifyRegistration templates). /auth/verify-token
survives for password resets only, and now requires a reset-password token
rather than accepting any signed JWT.

Roles: drop the users.role column and the four-value USER_ROLES enum. The
permissions table granted every role identical methods, and every
role === 'Super Admin' check was permanently true. The JWT no longer carries a
role claim.

Sandbox: remove sidecar/sandbox.ts and its five call sites. bwrap was selected
only for non-Super-Admin users, so it never ran. It was also not a usable agent
jail as written — --share-net, the project root (with .env) bound read-only,
and runuser dropping to the server's own uid. Rebuilding it for agent
containment would be a different construction, and git history keeps this one.

getHomeDir keeps its DATA_PATH meaning; the new getOwnerHomeDir resolves the
owner's real login home, which is what terminals, chats and task runs use.

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

scripts/migrate-auth-to-pg.ts

@@ -77,7 +77,6 @@ async function migrate() {
       .values({
         email: u.email,
         password: u.password,
-        role: u.role as 'Member' | 'Admin' | 'Owner' | 'Super Admin',
         status: u.status as 'Unverified' | 'Active' | 'Prospect' | 'Invited' | 'Blocked' | 'Banned' | 'Deleted',
         name: u.name,
         username: u.username,