feat(rewards): pay early finish points and top-up on proof

A linked PlayStation title no longer blocks. Its playtime never
proves a finish. An unproven Steam finish pays 10 early points,
the rest comes with proof. Back pay only from app.rewards.early-since.

readme.md

@@ -104,6 +104,7 @@ flowchart LR
     Rule --> Card["question card"]
     Answer["answer"] --> Backlog["BacklogService"] --> UserGame["user_game"] --> Trigger["V14 trigger: status log"] --> Settle["RewardService.settle"]
     Answer -->|"Frontend: GET /api/rewards/games/{appid}"| Settle
+    Sync["library sync"] --> LibraryActivityEvent --> Settle
     Answer -->|no| Snooze["user_game_question"]
 ```
 - **Hide games**: a user can hide a game, Steam or added by hand (e.g. a playtest or a tool). It leaves every list and number: library,
@@ -133,11 +134,14 @@ flowchart LR
   (old and new status, time, whether the user chose it), whatever code path made it. It starts with V14; older
   changes are not known.
 - **Pile Points** (`modules/rewards`): users earn points for playing games off the pile, in an append-only ledger
-  (`reward_ledger`, V26; the balance is the sum). No code path pays: a settle (on `GET /api/rewards/wallet`, on `GET /api/rewards/games/{appid}` and
+  (`reward_ledger`, V26; the balance is the sum). No code path pays: a settle (on `GET /api/rewards/wallet`, on `GET /api/rewards/games/{appid}`, after every sync (`LibraryActivityEvent`, own transaction, a failure only logs) and
   nightly at 02:30, `app.rewards.settle-cron`) derives rows from the status log, playtime days, achievements and pile
   snapshots, once per user, kind and game (`ref`). Rules and numbers: `RewardRules`; a Steam finish needs playtime and one
-  proof of fresh play (ending achievement or playtime around the finish, or half of the IGDB time played since the finish; old history pays nothing). The month bonus needs a finished game in that month. Games added by hand pay 15 for
-  a finish, at most 3 per ISO week. `GET /api/rewards/games/{appid}` (game page open, after every status save) settles, then answers the paid rows of the game and its set (`bookedNow` = written by this call) and one `NoPointsReason` per missing kind (`STARTED`, `FINISHED`, `COMPLETED`); the codes live in `RewardRules`, the Frontend only maps them to texts. The settle takes a per-user advisory lock. V26 also pays a one-time starter grant
+  proof of fresh play (ending achievement or playtime around the finish, or half of the IGDB time played since the finish). Without proof a Steam finish pays 10 early points (`FINISHED_EARLY`), only for finishes on or after
+  `app.rewards.early-since` (older unproven finishes pay only with proof); when proof arrives later, `FINISHED_TOPUP` pays the rest up to the full amount, once per game or set. PlayStation days never prove: a game linked to a PlayStation title pays by its own rules, only
+  PlayStation rows pay nothing. The month bonus needs a finished game in that month. Games added by hand pay 15 for
+  a finish. Manual finishes and early finishes share the cap of 3 per ISO week. `COMPLETED` needs a `FINISHED` or `FINISHED_TOPUP` row.
+  `GET /api/rewards/expected?appids=` (read-only, at most 200) answers the full finish value per game for the Questions cards. `GET /api/rewards/games/{appid}` (game page open, after every status save) settles, then answers the paid rows of the game and its set (`bookedNow` = written by this call) and one `NoPointsReason` per missing kind (`STARTED`, `FINISHED`, `COMPLETED`); the codes live in `RewardRules`, the Frontend only maps them to texts. The settle takes a per-user advisory lock. V26 also pays a one-time starter grant
   for finishes from before the status log. Shop: a whitelist of 57 looks (`ShopItem`; 45 buyable and 12 unlock-only) in eight slots, including animated completed effects, page backgrounds (CSS, SVG and two canvas engines in the Frontend),
   banner backgrounds (V27 widens `reward_equipped.slot`) and three buyable skins (full themes, slot `SKIN`). The unlock-only
   items (price 0, never sold): the settle books an `UNLOCK` row (ref = item code, 0 points) once a
@@ -218,6 +222,7 @@ ArchUnit role rules (`RoleAnnotationRules`) and `src/test/resources/contract/aut
 | Method | Path | Auth |
 |---|---|---|
 | `GET` | `/api/rewards/wallet` (balance, catalog, owned, equipped, last 50 ledger rows with the game name, unlock `progress` per track) | JWT |
+| `GET` | `/api/rewards/expected?appids=` (`{appid: points}`, the full finish value, 0 when paid; read-only, no settle; `400 TOO_MANY` over 200 appids) | JWT |
 | `POST` | `/api/rewards/purchases` (`{item}`; `200` wallet, `409 ALREADY_OWNED` / `NOT_ENOUGH_POINTS` / `NOT_FOR_SALE`) | JWT |
 | `GET` | `/api/rewards/progress/{track}/games?page=`, `/api/rewards/history/{kind}/{ref}/games?page=` (the games behind a track or a `MONTH` / `STREAK` bonus; `400 NOT_A_GAME_LIST`) | JWT |
 | `PUT` | `/api/rewards/equipped/{slot}` (`{item}`, null = take off; `200` wallet, `409 NOT_OWNED`, `400 WRONG_SLOT`) | JWT |