feat(follow): add feed link data and game endpoints (#52, #51)

Feed notes get profileName and appid; follows get lastActivityAt.
New GET /api/library/games/{appid}/preview: catalog data, any game.
New GET /api/public/profiles/library/games/{appid}: one profile game.

readme.md

@@ -67,7 +67,12 @@ To Be Played is split into four repositories:
   names, status moves collapsed per game, wishlist adds; at most 20 achievements per game, the newest unlocks stand for
   the new ones). `GET /api/inbox/{id}/details` shows them only while the reader still follows the subject, the subject
   is public, else `404`. Rows of a hidden part or a hidden game are left out. The nightly job at 03:15 deletes notes
-  older than 90 days (`app.inbox.keep-days`); the list shows the newest 50.
+  older than 90 days (`app.inbox.keep-days`); the list shows the newest 50. A note also carries `profileName` (the
+  subject's current name while the profile is public, else null), a detail line its `appid`, and each followed person
+  in `GET /api/follows` `lastActivityAt` (the newest digest note the caller got about them): the Frontend links the feed
+  to the game and to the profile view of that game. `GET /api/library/games/{appid}/preview` gives the catalog data of
+  any game (for "not in your library yet"), `GET /api/public/profiles/library/games/{appid}` one listed game of a public
+  profile, filtered by the ticket's sections; a hidden, removed or not owned game answers the same `404`.
 - **Backlog order**: every listed `BACKLOG` game (not removed, not hidden) has a row in `backlog_order (user_id,
   appid, position)`, kept by a database trigger on `user_game` like the status history: a game entering the backlog
   goes to the bottom, a game leaving it loses its row. V34 seeded the first order (priority HIGH, MEDIUM, rest, then
@@ -252,6 +257,7 @@ ArchUnit role rules (`RoleAnnotationRules`) and `src/test/resources/contract/aut
 | `GET` | `/api/library/dashboard-games?top=10&playing=8` (`{top, playing}`: the Dashboard tiles in one call, listed entries by set playtime, most first; `playing` only status PLAYING; same rows and order as `/games` with `sort=playtimeMinutes,desc` / `status=PLAYING`, no count query; limits clamped to 1..20; calls `syncIfStale` like `/games`) | JWT |
 | `PATCH` | `/api/library/games/{appid}/backlog` (only the sent fields; `null` clears one) | JWT |
 | `PUT`, `DELETE` | `/api/library/games/{appid}/corrections/{field}` (`{value}`; `name`, `image`, `speedrun`, `moods`, `endless`, `genres`, `time_to_beat` = `{normallyMinutes, completelyMinutes}`; `204`, `400 INVALID_CORRECTION`) | JWT, AUDITOR |
+| `GET` | `/api/library/games/{appid}/preview` (`{appid, name, imageUrl, genres, timeToBeat}`: catalog data of any game, a merged key answers with the kept key; `404 GAME_NOT_FOUND`) | JWT |
 | `GET` | `/api/library/catalog?q=&page=&size=` (every game some user still has, by name part, `PageDto` of `{appid, name, imageUrl, platforms}`; `q` at most 100 characters; size 20, 40 or 80) | JWT, AUDITOR |
 | `GET` | `/api/library/catalog/{appid}` (what the correction dialog reads: name, image, speedrun, moods, endless, genres, timeToBeat, corrections; `404 GAME_NOT_FOUND`) | JWT, AUDITOR |
 | `POST` | `/api/library/games/{appid}/merge` (`{otherAppid}`; `200 {appid}` = the key that stays, `400 SAME_GAME` / `STEAM_GAMES`, `404 GAME_NOT_FOUND`) | JWT, AUDITOR |
@@ -294,15 +300,16 @@ ArchUnit role rules (`RoleAnnotationRules`) and `src/test/resources/contract/aut
 | `GET` | `/api/library/sync-status`, `/summary`, `/activity`, `/wishlist`, `/steam-profile`, `/games-count` (`canSync`: a Steam ID or a PlayStation link; `sources`: the sources of the user's games) | JWT |
 | `GET` | `/api/public/profiles/library` | profile ticket |
 | `GET` | `/api/public/profiles/library/stats/games?key=&arg=&page=` (`403 NOT_SHARED`, `400 BAD_ARG`) | profile ticket |
+| `GET` | `/api/public/profiles/library/games/{appid}` (`{appid, name, imageUrl, status, playtimeMinutes, achievementsUnlocked, achievementsTotal, completionPercent}`, a field of a hidden section is null; `404 GAME_NOT_FOUND` for a hidden, removed or not owned game or when every field is hidden, `401 INVALID_TICKET`) | profile ticket |
 | `GET` | `/api/public/profiles/rewards` (`{equipped}`, the worn looks) | profile ticket |
 | `GET` | `/api/stats/public` (+ games per platform, top genres, finished per year) | public |
 | `GET` | `/api/stats/owners?appid=&key=&arg=&page=` (who owns a game in the set behind a community number, `key` default `OWNED`: `listed` display names only, `listedTotal`, `privateCount`, `includesYou`, not cached, `400 BAD_ARG`) | login |
 | `GET` | `/api/stats/public/games?key=&arg=&page=` (the games behind a landing number, per game `libraries` and `minutes`; `400 BAD_ARG`) | public |
-| `GET` | `/api/follows` (`{following: [{id, displayName}], followers: [{id, displayName}]}`, `id` is the follow row; a follower with a private profile has `displayName` null) | login |
+| `GET` | `/api/follows` (`{following: [{id, displayName, lastActivityAt}], followers: [{id, displayName, lastActivityAt}]}`, `id` is the follow row; a follower with a private profile has `displayName` null; `lastActivityAt` = the newest digest note the caller got about that person, null for followers and without a note) | login |
 | `PUT`, `DELETE` | `/api/follows/by-name/{displayName}` (follow, unfollow; `204`; PUT: `404 PROFILE_NOT_FOUND` for an unknown, private, blocked or deleted name, `400 FOLLOW_SELF`, `400 FOLLOW_LIMIT`) | login |
 | `DELETE` | `/api/follows/{id}` (unfollow, or remove a follower; only rows of the caller change; `204`) | login |
-| `GET` | `/api/inbox` (`{results: [{id, kind, displayName, newGames, achievements, statusChanges, wishlistAdds, createdAt, read, details}], unread}`, newest 50, `kind` `DIGEST` or `VISIBILITY`) | login |
-| `GET` | `/api/inbox/{id}/details` (`{results: [{kind, gameName, itemName, fromStatus, toStatus}]}`, `kind` `NEW_GAME`, `ACHIEVEMENT`, `STATUS` or `WISHLIST`; `404` for a note that is not the caller's or not open any more) | login |
+| `GET` | `/api/inbox` (`{results: [{id, kind, displayName, profileName, newGames, achievements, statusChanges, wishlistAdds, createdAt, read, details}], unread}`, newest 50, `kind` `DIGEST` or `VISIBILITY`) | login |
+| `GET` | `/api/inbox/{id}/details` (`{results: [{appid, kind, gameName, itemName, fromStatus, toStatus}]}`, `kind` `NEW_GAME`, `ACHIEVEMENT`, `STATUS` or `WISHLIST`; `404` for a note that is not the caller's or not open any more) | login |
 | `PUT` | `/api/inbox/read` (marks all read; `204`) | login |
 | `POST`, `PUT` | `/internal/accounts/deleted` (`{userIds}`; POST adds, PUT replaces the whole set; `204`) | service token |
 | `POST`, `PUT` | `/internal/accounts/states` (`{accounts: [{userId, steamId, displayName, blocked, roleChangedAt, listed, publicProfile, profileSections}]}`, `displayName`, `roleChangedAt`, `listed` and `publicProfile` optional (`listed`: Auth lists the user by name, kept in `listed_user`, `null` keeps it; `publicProfile`: the profile is public, kept as a row in `public_user` with `profileSections`, `null` keeps row and sections, `false` ends the follows of the user with one `VISIBILITY` note each; `profileSections` `null` = all shown), `displayName` at most 100 characters, kept in `account_name` for the audit log, `roleChangedAt` kept in `account_role_change`; POST updates, PUT replaces the whole set; `204`) | service token |
@@ -359,7 +366,7 @@ flowchart LR
     LibRepo -->|"own tables; picker also follow, public_user, account_name, blocked_user, deleted_user; inbox_note (PSN expiry notes)"| Db[("PostgreSQL tbp_core")]
     Stats -->|"listed_user_game, counted_user_game, game_mood, coming_game, user_game_status_change, deleted_user, blocked_user, listed_user, account_name, game_alias"| Db
     Follow -->|"follow, follow_digest, inbox_note, inbox_note_detail, public_user, sync_change, user_game_status_change, user_game_achievement, user_psn_trophy, wishlist_game, account_name"| Db
-    Inbox -->|"inbox_note, inbox_note_detail, follow, public_user, user_game"| Db
+    Inbox -->|"inbox_note, inbox_note_detail, follow, public_user, user_game, account_name, blocked_user, deleted_user"| Db
     Auth -->|"service token<br/>/internal/accounts"| Account
     Account -->|"per-user rows, deleted_user, blocked_user, listed_user, public_user, follow, account_name, user_seen_at"| Db
 ```