feat(library): soft delete removed games and add restore

Removed games could not come back (#39). Remove now sets removed_at
and restore clears it. V46 brings back PSN games removed before.

readme.md

@@ -243,6 +243,8 @@ ArchUnit role rules (`RoleAnnotationRules`) and `src/test/resources/contract/aut
 | `GET` | `/api/library/questions`, `/api/library/questions/count` (`{results: [{appid, name, imageUrl, question, status, playtimeMinutes, normallyMinutes, lastActivity}]}`, `{count}`) | JWT |
 | `POST` | `/api/library/questions/{appid}` (`{question, yes, rating?}`; `200 {next}`, `400 INVALID_ANSWER`, `404 GAME_NOT_FOUND`, `409 QUESTION_GONE`) | JWT |
 | `PUT` | `/api/library/games/{appid}/finished-hint` (`{dismissed: ENDING\|PLAYTIME}`, "Not yet"; `204`) | JWT |
+| `GET` | `/api/library/removed-games` (`{results: [{appid, name, imageUrl, source, platform, removedAt}]}`: the caller's removed `MANUAL` and `PSN` games, newest first) | JWT |
+| `POST` | `/api/library/games/{appid}/restore` (a removed game comes back with its old data; `204`, also when it is already back; `404 GAME_NOT_FOUND`, `409 STEAM_GAME`) | JWT |
 | `PUT` | `/api/library/games/{appid}/hidden` (`{hidden}`; Steam and manual games) | JWT |
 | `POST` | `/api/library/imports` (`{source: TEXT\|CSV\|SEARCH\|GALAXY\|GROUVEE\|HLTB\|PLAYNITE\|BOOKMARKLET, rows: [{title, platform, playtimeMinutes, status, igdbId}]}`, 1–1000 rows; `202 {id}` in `QUEUED`, `409 IMPORT_RUNNING`, `503 IGDB_OFF`) | JWT |
 | `GET` | `/api/library/imports` (`{imports}`, the last 20), `/api/library/imports/{id}` (status, progress counts, `ahead` while it waits in a queue, `attempts`; the rows with their candidates while `READY`) | JWT |
@@ -647,11 +649,21 @@ A game the user adds by hand comes from IGDB (`ManualGameService`). Steam games
 `user_game.source` (`GameSource`) says who owns the row. The sync never changes or removes a `MANUAL` row, with
 one exception: when the user later owns the game on Steam under the same appid, the sync takes the row over: it becomes
 `STEAM`, and status, rating and notes stay. `PSN` rows (a PlayStation import, see below) live the same way. Only `MANUAL` and `PSN` rows can be edited (`PUT /api/library/games/{appid}/manual`)
-or deleted (`DELETE /api/library/games/{appid}`). Time to beat uses the Steam appid for positive keys and the IGDB
+or removed (`DELETE /api/library/games/{appid}`, soft: it sets `removed_at`, the row keeps status, rating, notes
+and history) and restored (`POST /api/library/games/{appid}/restore`, see the diagram). Time to beat uses the Steam appid for positive keys and the IGDB
 id for negative keys. Search and add check both keys of a game. A game added under minus its IGDB id can still get
 a second row when IGDB learns its Steam appid later and the user owns it on Steam; an auditor then merges the two
 (see "Merging duplicates").
 
+```mermaid
+stateDiagram-v2
+    [*] --> Listed: add / sync
+    Listed --> Removed: DELETE /games/{appid} (MANUAL, PSN)
+    Removed --> Listed: POST /games/{appid}/restore or Undo
+    Removed: removed_at set, data kept
+    Removed: PSN sync skips the row
+```
+
 ### Imports
 
 Many games at once (V22, `GameImportService`): a list, a CSV or several picks of the game search become one
@@ -723,8 +735,10 @@ project ships it; all values in `app.psn.*`). `PsnAccountService` in `library` h
   - Every `LINKED` or `STEAM_OWNED` title also keeps its own platform, minutes and last played in `user_psn_title` (V44),
     so the detail shows PlayStation play next to Steam's on a shared row. The Steam row's own playtime stays Steam's.
   - A `LINKED` title updates its row (`source = PSN`, not removed): playtime, `last_played_at`, `PLAYTIME` changes and the
-    playtime history; `playtime_2weeks` is the sum of the history of the last 14 days. A game the user deleted stays
-    `LINKED` and is not added again. A game also owned on Steam stays one row (the Steam row wins).
+    playtime history; `playtime_2weeks` is the sum of the history of the last 14 days. A game the user removed stays
+    `LINKED` and the sync does not add it again; its row stays removed, so the sync skips it until the user restores it:
+    a restore takes the stored title play (`psn_title_play`) and the sync updates the row again. Flyway V46 gave games
+    removed before (soft delete) a removed `PSN` row and turned a `MANUAL` row re-added on a `LINKED` key back to `PSN`. A game also owned on Steam stays one row (the Steam row wins).
   - The first run of a user (no `user_psn_title` yet) is a baseline like the first Steam sync: its adds are a count in
     `sync_result.imported_games`, not a list. PSN changes share the `sync_result` of the Steam part, so the banner and the
     follow digest need no change.