feat(成就): 下架三个拿不到的成就、理顺稀有度和图标；接口多给本班几人有和「本班」卡片

- 0032：下架六边形战士（判题机只剩 3 种语言）、坚持三天/一周（按天算基本拿不到）；
  不撞南墙改白银、屡败屡战改黄金；百发百中换 💯、屡败屡战换 💪，不再和别的撞图标；
  代码行数只算做对的、空行不算，并按新口径重算所有人；已经拿到的一个不收回
- 奖杯收藏家只数上架的成就（判题结算、补发重算、0032 存量一起改）
- GET /achievements：每个成就带全站几人有、本班几人有；看自己时带「本班」（最近拿到、成就最多前五、自己第几）；
  隐藏成就同一串拿到一档就整串亮出来；连续几周给「现在连着几周」而不是历史最长
- 删掉只有旧成就页在用的 /achievements/summary

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

apps/api/src/db/0032_achievement_cleanup.sql

@@ -0,0 +1,60 @@
+-- 成就清单的五处毛病（我的成就重设计，2026-10-13）。只改配置和进度，已经拿到的一个不收回。
+--
+-- 1. 下架拿不到的：六边形战士要用过 5 种语言，判题机只剩 C / C++ / Python；
+--    坚持三天 / 一周按天算，学生跟着课表来，基本拿不到（按周的「周周向上」那一串已经顶上了）。
+UPDATE "achievement" SET "visible" = false
+WHERE ("metric" = 'languages_used' AND "threshold" = 5) OR "metric" = 'max_ac_streak_days';
+--> statement-breakpoint
+UPDATE "achievement" SET "description" = 'C、C++、Python 都用过'
+WHERE "metric" = 'languages_used' AND "threshold" = 3;
+--> statement-breakpoint
+-- 2. 稀有度倒挂：错 10 次才做对是黄金、错 20 次反而是白银
+UPDATE "achievement" SET "rarity" = 'silver' WHERE "metric" = 'max_wa_before_ac' AND "threshold" = 10;
+--> statement-breakpoint
+-- 3. 图标撞了：屡败屡战和持之以恒都是火，百发百中和一发入魂是同一个靶子（noto:direct-hit 是 bullseye 的别名）
+UPDATE "achievement" SET "rarity" = 'gold', "icon" = 'noto:flexed-biceps'
+WHERE "metric" = 'max_wa_before_ac' AND "threshold" = 20;
+--> statement-breakpoint
+UPDATE "achievement" SET "icon" = 'noto:hundred-points'
+WHERE "metric" = 'first_try_ac_count' AND "threshold" = 100;
+--> statement-breakpoint
+-- 4. 代码行数只算做对的、空行不算：原来交什么都算，贴一大段就是「长篇巨制」
+UPDATE "achievement" SET "description" = '做对的代码有 ' || "threshold" || ' 行（空行不算）'
+WHERE "metric" = 'max_code_lines';
+--> statement-breakpoint
+-- 按新口径重算所有人的 max_code_lines（判题结算里的口径见 services/achievements.ts）：
+-- 不含比赛，做对 = ACCEPTED(0) / AST_CHECK_FAILED(10)
+UPDATE "user_stat" AS target
+SET "metrics" = jsonb_set(target."metrics", '{max_code_lines}', to_jsonb(coalesce(fresh.n, 0)))
+FROM (
+  SELECT st."id", m.n
+  FROM "user_stat" st
+  LEFT JOIN (
+    SELECT s."user_id", max((
+      SELECT count(*) FROM regexp_split_to_table(s."code", E'\n') AS line
+      WHERE btrim(line, E' \t\r') <> ''
+    ))::int AS n
+    FROM "submission" s
+    WHERE s."contest_id" IS NULL AND s."result" IN (0, 10)
+    GROUP BY s."user_id"
+  ) m ON m."user_id" = st."user_id"
+) fresh
+WHERE target."id" = fresh."id"
+  AND (target."metrics" -> 'max_code_lines') IS DISTINCT FROM to_jsonb(coalesce(fresh.n, 0));
+--> statement-breakpoint
+-- 5. 奖杯收藏家数的「已拿到几个」只数上架的（判题结算和 refreshUnlockedCount 同步改了）
+UPDATE "user_stat" AS target
+SET "metrics" = jsonb_set(target."metrics", '{achievement_unlocked_count}', to_jsonb(fresh.value))
+FROM (
+  SELECT s."id", coalesce(c.value, 0) AS value
+  FROM "user_stat" s
+  LEFT JOIN (
+    SELECT ua."user_id", count(*)::int AS value
+    FROM "user_achievement" ua
+    JOIN "achievement" a ON a."id" = ua."achievement_id"
+    WHERE a."rarity" <> 'platinum' AND a."visible"
+    GROUP BY ua."user_id"
+  ) c ON c."user_id" = s."user_id"
+) fresh
+WHERE target."id" = fresh."id"
+  AND (target."metrics" -> 'achievement_unlocked_count') IS DISTINCT FROM to_jsonb(fresh.value);

apps/api/src/db/meta/_journal.json

@@ -225,6 +225,13 @@
       "when": 1791766110876,
       "tag": "0031_tutorial_project_and_problems",
       "breakpoints": true
+    },
+    {
+      "idx": 32,
+      "version": "7",
+      "when": 1791821976519,
+      "tag": "0032_achievement_cleanup",
+      "breakpoints": true
     }
   ]
 }