fix(cost): bill a session outside every workspace to its Linux account's user

A script's claude -p in a temp folder (the SG Flow eval runner strips the
pane's env) had no workspace, so its spend reached nobody's Today, the Users
page or a spend quota — ~$57 of a $74 day was missing from the status bar.

sessions.account records the Linux account a session ran as (the hook's
peer uid, else its folder for poller-made and old rows); a session no
workspace owns is owned by that account's user — a member's to them, the
host's to the admin ticked 'Owns this server's host account' (or the only
admin). Workspace ownership still wins.

client/src/lib/api.ts

@@ -800,6 +800,8 @@ export type UserPatch = {
   addWorkspaces?: number[];
   removeWorkspaces?: number[];
   signOut?: true;
+  /** Owns the host's Linux account: its sessions outside every workspace bill to them (admins only). */
+  hostAccount?: boolean;
   /** Their own spend quota (`default` = the default applies). */
   quota?: UserQuotaSetting;
 };
@@ -983,6 +985,8 @@ export type AuthUser = {
   createdAt?: string;
   /** An admin gave this password: the user must choose their own before anything else. */
   mustChangePassword?: boolean;
+  /** Owns the host's Linux account (server/lib/session-account.js) — absent from an older server. */
+  hostAccount?: boolean;
 };
 export type AuthState = { mode: "local" } | { mode: "server"; user: AuthUser | null };
 /** GET /api/me/prefs — the signed-in account's own UI preferences (localStorage keys). */