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>

src/servers/api/users/provision.ts

@@ -83,10 +83,3 @@ async function seedShellConfigs(homeDir: string): Promise<void> {
   // Ensure .local/bin exists
   mkdirSync(join(homeDir, '.local', 'bin'), { recursive: true });
 }
-
-export function deprovisionUserEnvironment(email: string, _username: string): boolean {
-  // User data directories are intentionally kept on disk.
-  // This function exists for API compatibility.
-  console.log(`[provision] deprovision called for ${email} (no-op, data kept on disk)`);
-  return true;
-}