Record the SQLite APPLY fix for leaderboard endpoints

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/plan.md

@@ -543,7 +543,7 @@ loads, and `GET /player/76561199407393962` returns 404 rather than 500.
 
 ### Phase 3: Importer
 
-**Importer done 2026-11-09** (`pleb/main` at `737575b`, not pushed yet). Usage
+**Importer done 2026-11-09** (`pleb/main` at `e3f991c`, pushed to Gitea). Usage
 and the full file → table mapping are in the fork's `MIRROR.md`. A full import
 takes about 11 s, and an unchanged rerun writes 0 rows. What differs from the
 steps below:
@@ -580,14 +580,14 @@ archived upstream responses, on a scratch DB with `ASPNETCORE_ENVIRONMENT=Mirror
   triangle ratings.
 - `/accgraph` and `/history/triangle` match. `/score/statistic/{id}` redirects
   to the local file.
-- **Open: `/leaderboard/{id}` and `/leaderboard/scores/{id}` return 500.**
-  `LeaderboardController.GeneralScores` projects
-  `Player.Clans.OrderBy(…ClanOrder…).Take(1)`, which needs SQL `APPLY`, and
-  SQLite has none. The same pattern appears about 8 times, in
-  `ScoreController`, `ReplayController`, `LeaderboardController` and
-  `ClanUtils`. Fix it in a separate server commit before phase 4. For example,
-  skip the clan projection in MirrorMode (there are no clans), or move the
-  ordering client-side.
+- `/leaderboard/{id}` and `/leaderboard/scores/{id}` first returned 500.
+  About 10 projections order `Player.Clans` by an expression over the outer
+  row's `ClanOrder`, which needs SQL `APPLY`, and SQLite has none. **Fixed**
+  in `e3f991c`: `Utils/MirrorQueryInterceptor.cs`, an EF query interceptor
+  registered only in MirrorMode, rewrites any ordering of `Player.Clans` to
+  ordering by clan id. One file instead of patching every call site; the
+  mirror has no clans, so the order doesn't matter. The leaderboard,
+  clan-ranking and context variants now return 200.
 
 The check below (stock website) is still to do in phase 4.