feat(library): picker for what to play next and a status-only update

GET /api/library/picker returns random backlog games for a time budget, HIGH priority first. PUT /games/{appid}/status changes only the status, so the picker does not need the game detail (and its Steam calls) to keep rating, notes and priority.

readme.md

@@ -17,6 +17,8 @@ To Be Played is split into three repositories:
   sync. Resilience4j retries and rate-limits every Steam call; Caffeine caches game counts and player summaries.
 - **Backlog**: status (`BACKLOG`, `PLAYING`, `FINISHED`, `COMPLETED` = 100 %, `DROPPED`), rating 1–5, notes, priority,
   filters and sorting. "Pile of Shame" summary with a random suggestion of what to play.
+- **Picker**: up to 10 random backlog games for a time budget (IGDB normal time to beat), HIGH priority first, then
+  MEDIUM, then the rest. Games already shown can be excluded for a reroll.
 - **Playtime history**: one row per game and day, for the activity view and the "most played in the last two weeks"
   dashboard banner.
 - **Wishlist**: synced from Steam with store price and discount.
@@ -38,7 +40,9 @@ on normal endpoints; the profile ticket is accepted only by `GET /api/public/pro
 |---|---|---|
 | `GET` | `/api/library/games`, `/api/library/games/{appid}` | JWT |
 | `PUT` | `/api/library/games/{appid}/backlog` | JWT |
+| `PUT` | `/api/library/games/{appid}/status` (status only, keeps rating, notes, priority) | JWT |
 | `POST` | `/api/library/sync` | JWT |
+| `GET` | `/api/library/picker?maxMinutes=&count=&exclude=` | JWT |
 | `GET` | `/api/library/sync-status`, `/summary`, `/activity`, `/wishlist`, `/steam-profile`, `/games-count` | JWT |
 | `GET` | `/api/public/profiles/library` | profile ticket |
 | `GET` | `/api/stats/public` | public |
@@ -102,7 +106,7 @@ Runs unit, WebMvc, persistence and integration tests plus the ArchUnit rules. Ne
 
 ## Roadmap
 
-- "What to play next" picker: time budget and mood on top of the current random suggestion.
+- Mood filter for the picker (needs genres or themes from IGDB).
 - Achievement summary per game and library-wide, "closest to 100 %".
 - Sale alerts for wishlist games.
 - Move `steam_adapter` DTOs out of `api`, then turn on strict module independence in ArchUnit.