fix(rewards): let manual finish open COMPLETED for Steam edition

A paid FINISHED_MANUAL on a set edition blocked COMPLETED for the
Steam game forever. It now opens COMPLETED, but only when the Steam
game's first finish is on or after app.rewards.early-since. Refs #35

readme.md

@@ -143,7 +143,8 @@ flowchart LR
   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.
+  a finish. Manual finishes and early finishes share the cap of 3 per ISO week. `COMPLETED` needs a `FINISHED`, `FINISHED_TOPUP` or `FINISHED_MANUAL` row on the game or its set, so a manual edition's finish opens it for the Steam edition, but only when the Steam game's own first finish
+  (first `FINISHED`/`COMPLETED` status change) is on or after `app.rewards.early-since`; a manual game itself never gets it.
   `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