feat(admin): per-user finance panel — balances, benefits, risk, ledger

The /_gm user card gains a Finance panel: an account's chip balances per
funding segment, benefits per origin (hints, no-ads until/forever), the
recorded refund risk (abuse flag + floor-0 loss), and the append-only ledger
history newest-first. Backed by a new payments.AccountStatement read straight
from the materialized tables + the ledger (uncached — an admin, rare view).

Folds the agreed admin / reports / catalog plan into PLAN.md (the PR stack:
this panel, then the catalog editor, admin grant, refund + ledger export) and
moves the tournament-entry storage design to the tournament stage.

backend/README.md

@@ -139,7 +139,10 @@ the resolved, weighted campaign feed for an **eligible** viewer (no active **no-
 applicable in the current context and no **`no_banner`** role; the message language picked by
 `preferred_language`); changing those inputs
 publishes a `notify` `banner` re-poll signal so the client shows/hides it in place.
-The same gate drives the post-move interstitial config (`Profile.ads`, `adsFor`). The shared wire
+The same gate drives the post-move interstitial config (`Profile.ads`, `adsFor`). The user card
+also carries a **finance panel** (`payments.AccountStatement`): the account's chip balances per
+funding segment, benefits per origin, the recorded refund risk, and the append-only ledger history
+(newest first) — read straight from the payments tables, uncached. The shared wire
 contracts live in the sibling [`../pkg`](../pkg) module.
 
 **Account linking & merge** (`/api/v1/user/link/*`). `internal/link`