feat(account): Steam ID and blocked state from Auth (V25)

A blocked user gets no sync and leaves the landing stats. A new or removed Steam ID stops the nightly sync of the old one. No token check in Core: the token lives until it expires.

readme.md

@@ -129,6 +129,7 @@ method calling another service's method that needs more.
 | `GET` | `/api/public/profiles/library` | profile ticket |
 | `GET` | `/api/stats/public` | public |
 | `POST`, `PUT` | `/internal/accounts/deleted` (`{userIds}`; POST adds, PUT replaces the whole set; `204`) | service token |
+| `POST`, `PUT` | `/internal/accounts/states` (`{accounts: [{userId, steamId, blocked}]}`; POST updates, PUT replaces the whole set; `204`) | service token |
 | `POST` | `/internal/accounts/purge` (`{userIds}`), `/internal/accounts/prune` (`{knownUserIds}`, not empty) | service token |
 | `GET` | `/api/version` (`{commit, builtAt}` of the running image, from the CI build; `dev` locally) | public |
 
@@ -173,9 +174,9 @@ flowchart LR
     Igdb -->|"OAuth token"| Twitch["Twitch"]
     Speedrun --> SpeedrunApi["speedrun.com API"]
     LibRepo --> Db[("PostgreSQL tbp_core")]
-    Stats -->|"listed_user_game, deleted_user"| Db
+    Stats -->|"listed_user_game, deleted_user, blocked_user"| Db
     Auth -->|"service token<br/>/internal/accounts"| Account
-    Account -->|"per-user rows, deleted_user"| Db
+    Account -->|"per-user rows, deleted_user, blocked_user, user_seen_at"| Db
 ```
 
 | Module | Content |
@@ -183,15 +184,16 @@ flowchart LR
 | `library` | Sync, backlog, manual games, imports, playtime history, wishlist, achievements, public profile data |
 | `stats` | Public numbers for the landing page |
 | `version` | `GET /api/version`: commit and build time of the running image |
-| `account` | Deleted accounts, driven by Auth: tombstones in `deleted_user`, purge and orphan prune of the per-user rows |
+| `account` | Driven by Auth: tombstones in `deleted_user`, purge and orphan prune of the per-user rows; blocks in `blocked_user`, Steam ID changes stop the nightly sync |
 | `steam_adapter` | Steam Web API client, availability check of Steam CDN pictures |
 | `igdb_adapter` | IGDB client (Twitch OAuth): time to beat, game tags for moods, release years, game search |
 | `speedrun_adapter` | speedrun.com client: game search by name, verified runs |
 
 **One shared schema.** All modules use one database `tbp_core`, and some read or write another module's tables in
-SQL, which ArchUnit cannot see: `stats` reads `listed_user_game`, `steam_game` and `deleted_user`; `account` deletes
-the per-user rows of the library tables (`AccountCleanupRepository`; a new library table with `user_id` goes into
-its list); `library` reads `deleted_user`. A module that moves to its own service takes these reads along as calls.
+SQL, which ArchUnit cannot see: `stats` reads `listed_user_game`, `steam_game`, `deleted_user` and `blocked_user`; `account`
+deletes the per-user rows of the library tables (`AccountCleanupRepository`; a new library table with `user_id` goes
+into its list) and writes `user_seen_at` and `last_synced_at` of `user_steam_sync` (`AccountStateRepository`); `library`
+reads `deleted_user` and `blocked_user`. A module that moves to its own service takes these reads along as calls.
 The listed rule ("still owned, not hidden") is `UserGameRepository.LISTED` for JPQL and the view
 `listed_user_game` for native SQL; V24 says what a migration of `user_game` must do with the view.
 
@@ -222,7 +224,7 @@ Inside a module: `api` (controllers, DTOs), `service` (business logic), `domain`
    dates finished games by the unlock of their ending achievement
    (`FinishedEstimateService`, `user_game.finished_at_estimate`).
 3. `LibrarySyncWorker` runs on the background pool. `user_steam_sync` lets only one run per user start, and none for
-   a user in `deleted_user`.
+   a user in `deleted_user` or `blocked_user`.
 4. The worker loads the wishlist and the owned games from Steam. It updates `steam_game` and `user_game`, adds
    the playtime growth of the day to `user_game_playtime_day`, and soft-deletes Steam games the user no longer
    owns. The growth counts at most Steam's playtime of the last two weeks, so a game seen for the first time brings
@@ -310,6 +312,16 @@ flagged set (`PUT`), then `purge` for users flagged 30 days ago (only tombstoned
 user ids, which removes the rows of users Auth does not know (refused for more than
 `app.account-cleanup.max-orphans`, default 5). `app.account-cleanup.dry-run` (default `true`) only counts the rows.
 
+### Blocked users and Steam ID changes
+
+Auth sends a user's state (`POST /internal/accounts/states`) after a Steam link, an unlink, a Steam ID another account
+took by a verified link, a block and an unblock; its nightly job sends every user (`PUT`). A blocked user is in
+`blocked_user`: no nightly sync, no new sync run, not in the landing stats. The access token still works in Core until
+it expires (max 15 min). A new Steam ID or no Steam ID takes the user out of the nightly sync; the next visit syncs
+the ID of the token (Core's copy changes only then, so that sync sees the change and drops the old account's games). A visit with an access token that still has the old ID (max 15 min) can sync it once
+more and put the user back on the nightly list; the nightly `PUT` at 04:15 takes the user off again, so at most one
+nightly sync (23:55) runs with the old ID. Unblock and the nightly `PUT` lift the block.
+
 ### Manual games next to Steam games
 
 A game the user adds by hand comes from IGDB (`ManualGameService`). Steam games and manual games share