feedback7 stats: a match left right away stays in the history but does not count; bounded storage, corrupt-data handling, the page reworked as 干员调配-style tabs, the settlement re-view without the app store (PR #323 by @2321Robin, owner's decision of 2026-10-08); golden: unchanged

Counting rule (ui/stats.js countsTowardStats, the owner's decision of 2026-10-08: do not count the matches entered and left
right away, but keep them in the history): a settled match (m.result arrived) always counts; a match given up (放弃模拟)
counts once at least one of the player's battles had finished — a round cleared (the server's own rule, platform.js
_quit: leaving while round k runs has passed k - 1, in its settlement k) or already eliminated. Anything earlier is
history only: marked 中途退出 and 不计入统计, dimmed, listed in 对局记录, left out of every aggregate (games, wins, win
rate, strategy table, titles, rounds, time, combat totals); 总览 says how many were left out.
- A leaver gets no m.result, so the page records the match itself: quitMatch (放弃模拟) → recordQuit builds an
  `end: 'quit'` record from the app state and a tracker (observeMatch, installed in main.js) that remembers when the page
  first saw the match and the last round the player was seen alive in. No record for a spectator seat, a match with its
  settlement already there, a match the page never saw; matches the server ended and closed tabs are not recorded.

Defects of PR #323 as submitted, reproduced (scratchpad/w7-stats-notes/repro-pr-bugs.mjs, loads-check*.mjs) and fixed:
- the title screen loaded all 16 game data files (5.3 MB) at boot: <StatsHost/> called useGameData() at mount; now the
  host renders nothing until opened, the overview reads config / bands / assets and the settlement re-view loads the rest
  when opened (the title screen loads the same 3 files as before);
- importing a file put the list oldest first (the page shows the first 20 as the newest and the cap would drop the
  newest); the list is newest first everywhere, also when loaded from storage;
- recordResult wrote over the envelope of a NEWER build (a downgrade, against the PR's own rule); it refuses now, as
  saveStats does;
- 1000 four-player records are ~7.2 M characters (the PR's ~1.5 kB/record is a solo match) against a ~2.5 M-character
  quota: MAX_RECORDS 1000 stays, plus a 800 000-character budget (the oldest go first), and only the newest 30 records
  keep their rows (lineup, bonds, teammates' names; the replay needs them) — older ones are compacted to the player's own
  summary row (~620 characters), a refused write retries with half the history; unknown fields and oversized values are
  dropped (a strict schema), import files are bounded (8 MB);
- the re-view clobbered the app store (match.public / match.result, the route, the music); ResultScreen is split into
  ResultScreen (the store) and ResultView (props: result, myId, back label), so the stats page renders a stored match
  itself; a 自选 pick and a 补位 stand-in were dropped from the stored lineup (the replayed card drew the plain
  operator); DIFFICULTY_NAMES were not translated; a band cell was a display:flex <td>; the overlay stayed open when a
  co-op match started; the 清空 two-step blink was replaced by the shared confirm dialog.
- Corrupt storage: unreadable data is moved to sp.pref.stats.damaged and the page says so; damaged rows are dropped and
  counted; duplicates, an oversized or unsorted list are repaired on load; a pre-`end` (PR-era) envelope reads as settled.

UI: a full-screen overlay in the grammar of 干员调配 (top bar with 返回 / four tabs 总览 · 策略 · 战斗累计 · 对局记录 /
导出 导入 清空, a note line saying the data stays in this browser and that teammates' names are stored too), text sizes
with max(.xxrem, N px) for phones in landscape, a 50-row history page with 显示更多, a pass-rate bar, a per-difficulty
table in order; the entries use a new `chart` icon (not the ping bars), the title screen's sits beside the language menu
(the connection row has no room: it squeezed the gear and wrapped the status text), the lobby / room buttons show the
icon alone below 700 px (the room's title ran under the label at 640 px). docs/PLAYING.md §12, README row; 41 + 25 UI
strings in en / ja / ko / zh-TW (the PR's four unused ones removed).

Tests: test/ui/stats.test.js 44 / 44 (counting rule per phase, quit records, bounds, corrupt / old / newer storage,
import order, aggregation, the replay payload); test/ui/stats.e2e.test.js (opt-in SP_E2E=1, real server, headless Chrome:
seeded history on 1920×1080 and 844×390, the re-view, export / import / clear, corrupt and newer storage, and the real
flows: a solo match given up in the briefing is history only, one given up after round 1 counts, a settled match is
recorded once and not again after a reload) 6 / 6; lint 0 errors, i18n extract 0 / check --all --strict clean,
check:imports, typecheck, docs and version tests, golden unchanged.

public/js/ui/components.js

@@ -55,6 +55,8 @@ export const ICONS = {
   users: { d: 'M9 4a3.5 3.5 0 1 1 0 7 3.5 3.5 0 0 1 0-7zM2 20a7 6.5 0 0 1 14 0zM16.5 5a3 3 0 1 1 0 6 3 3 0 0 1 0-6zm.9 8.1A6.5 6 0 0 1 22.5 20H18a8.6 8 0 0 0-2.4-6.1 6 6 0 0 1 1.8-.8z' },
   rook: { d: 'M5 3h3v2h2V3h4v2h2V3h3v5l-2 2v7l2 2v2H5v-2l2-2v-7L5 8z' },
   signal: { d: 'M2 17h3v4H2zm6-4h3v8H8zm6-4h3v12h-3zm6-4h3v16h-3z' },
+  // 统计 (the stats page's entry): three columns on a baseline — apart from `signal`, the ping bars
+  chart: { d: 'M4 12h4v7H4zm6-6h4v13h-4zm6 3h4v10h-4zM3 20h18v2H3z' },
   refresh: { d: 'M12 4a8 8 0 0 1 7.4 5H17v2h6V5h-2v2.3A10 10 0 0 0 2 12h2a8 8 0 0 1 8-8zm0 16a8 8 0 0 1-7.4-5H7v-2H1v6h2v-2.3A10 10 0 0 0 22 12h-2a8 8 0 0 1-8 8z' },
   snow: { d: 'M11 2h2v4.2l2.3-2.3 1.4 1.4-3.7 3.7v2h2l3.7-3.7 1.4 1.4-2.3 2.3H22v2h-4.2l2.3 2.3-1.4 1.4-3.7-3.7h-2v2l3.7 3.7-1.4 1.4-2.3-2.3V22h-2v-4.2l-2.3 2.3-1.4-1.4 3.7-3.7v-2H9l-3.7 3.7-1.4-1.4L6.2 13H2v-2h4.2L3.9 8.7l1.4-1.4L9 11h2V9L7.3 5.3l1.4-1.4L11 6.2z' },
   chevronRight: { d: 'M8.6 5 7.2 6.4 12.8 12l-5.6 5.6L8.6 19l7-7z' },

public/js/ui/matchChrome.js

@@ -12,6 +12,7 @@ import { net } from '../net.js';
 import { store, useStore, shallowEqual, emptyMatch, createStore, isSpectating } from '../store.js';
 import { GIcon } from './gameComponents.js';
 import { GuideButton } from './guide.js';
+import { recordQuit } from './stats.js';
 import { t, tParts, N_ } from '../../../shared/i18n.js';
 
 /**
@@ -37,18 +38,27 @@ export const awayEnds = (s, prev) => (!!prev?.match?.public && !s?.match?.public
 store.subscribe((s, prev) => { if (awayStore.get().away && awayEnds(s, prev)) awayStore.set({ away: false }); });
 
 /**
- * Leave the match for good (g.leave → room.leave), then drop local room/match state.
+ * Leave the match for good (g.leave → room.leave), then drop local room/match state. The server sends a leaver no
+ * settlement, so the page records the match itself before it is cleared (本机统计, ui/stats.js recordQuit: a 中途退出
+ * entry of the history; it counts only when a round had been cleared) — once the leave went through.
  * @returns {Promise<void>}
  */
 export async function quitMatch() {
+  const before = store.get();
+  let left = false;
   try {
     try { await net.request('g.leave', {}); } catch (err) {
       if (err?.code !== 'NOT_IN_ROOM' && err?.code !== 'WRONG_PHASE' && err?.code !== 'OFFLINE') throw err;
     }
     try { await net.request('room.leave', {}); } catch (err) { if (err?.code !== 'NOT_IN_ROOM' && err?.code !== 'OFFLINE') throw err; }
+    left = true;
   } catch (err) {
     toastError(err);
   } finally {
+    // (a settlement that arrived while the leave was in flight is the match's record already)
+    if (left && !store.get().match.result) {
+      try { recordQuit(before); } catch (err) { console.warn('[stats] quit record failed', err); }
+    }
     store.set({ room: null, match: emptyMatch() });
   }
 }

public/js/ui/stats.js

@@ -1,35 +1,56 @@
-// Local match statistics: every finished match the local player took part in is appended as one record to
-// localStorage (`sp.pref.stats`, the loadPref/savePref convention of store.js). Per-browser only — the server
-// keeps matches in memory and has no identity, so there is nowhere else for cross-match numbers to live; the
-// stats page labels itself 本机数据 and offers JSON export / import for moving between devices.
+// Local match statistics: every match the local player took part in is appended as one record to localStorage
+// (`sp.pref.stats`). Per-browser only — the server keeps matches in memory and has no identity, so there is nowhere
+// else for cross-match numbers to live; nothing here is ever sent anywhere. The stats page labels itself 本机数据 and
+// offers JSON export / import for moving between devices. (Ported from PR #323 by @2321Robin, reworked for 0.2.2.)
 //
-// The record keeps everything the settlement offers (m.result is free-form, server/match/results.js buildResult):
-// the match frame (difficulty, mode, boss, seed, duration, hidden-core outcome, reason) plus one row per player
-// — band, title (评语), lineup, bonds and the full stat block — even where today's page aggregates only a part.
-// Whatever a future statistics view needs should already be in the record; display is the only thing that lags.
+// Two kinds of record (`end`):
+//   'settled'  the match reached its settlement: m.result arrived (server/match/results.js buildResult). The record
+//              keeps what the settlement offers — the match frame (difficulty, mode, boss, seed, duration, hidden-core
+//              outcome, reason) and one row per player (band, title, lineup, bonds, the stat block) — so the page can
+//              re-view the settlement screen (recordToResult).
+//   'quit'     the player gave up (放弃模拟) before the settlement; the server sends a leaver nothing, so the record is
+//              built from what the client knew at that moment (buildQuitRecord): the frame, the player's own row, the
+//              rounds cleared. It is listed in the history, marked 中途退出, and cannot be re-viewed.
 //
-// Format evolution: the envelope carries a version (`STATS_VERSION`); `migrateStats` walks records through a
-// chain of per-version steps and every loaded / imported record passes `normalizeRecord`, which fills defaults
-// for missing fields and PRESERVES unknown ones — so data written by an older build reads fine after an
-// upgrade, and fields added by a newer writer survive a round-trip through this one. An envelope from a newer
-// version than this build is refused (never silently downgraded and written back).
+// What counts (countsTowardStats, the owner's decision of 2026-10-08: a match entered and left right away must not
+// count): every aggregate — games, wins, win rate, hidden core, best round, time played, the strategy table, titles
+// and the combat totals — is taken over the records that count. A settled record always counts. A quit record counts
+// once at least one of the player's own battles had finished — a round cleared (the server's rule: leaving while
+// round k runs has passed k − 1 rounds, leaving in its settlement k) or already eliminated. A match left earlier is
+// history only.
 //
-// Pure logic, no Preact / DOM: Node-testable (test/ui/stats.test.js); localStorage is touched only through
-// loadStats / saveStats.
+// Bounded storage: at most MAX_RECORDS matches and MAX_CHARS characters of JSON. Only the newest FULL_KEEP records
+// keep their full rows (lineups, bonds, teammates' names — what the settlement replay needs); older ones are compacted
+// to the player's own summary row, which is all the aggregates read. The oldest records go first when a budget is hit,
+// and a write the browser refuses shrinks the list further instead of failing. Teammates' display names are part of
+// the newest records and of an export file: they stay on this device unless the player exports them.
+//
+// Format evolution: the envelope carries a version (`STATS_VERSION`); `migrateStats` walks records through a chain of
+// per-version steps and every loaded / imported record passes `normalizeRecord`, a strict schema: missing fields get
+// defaults, unknown fields and oversized values are dropped, a row it cannot salvage is dropped. An envelope from a
+// NEWER version than this build is refused (never downgraded and written back); an unreadable one is set aside
+// (`sp.pref.stats.damaged`) and the history starts again.
+//
+// Pure logic, no Preact / DOM: Node-testable (test/ui/stats.test.js); localStorage is touched only by loadStats /
+// saveStats / their helpers.
 
-import { loadPref } from '../store.js';
-import { t } from '../../../shared/i18n.js';
+import { PHASE } from '../../../shared/constants.js';
 
 /** Current record-envelope version (bump + add a MIGRATIONS step when the record shape changes). */
 export const STATS_VERSION = 1;
 /** localStorage key under the app's `sp.pref.` prefix (store.js loadPref). */
 export const STATS_PREF_KEY = 'stats';
-/** Oldest records are dropped beyond this (rough sizing: ~1.5 kB/record ⇒ ~1.5 MB of a ~5 MB quota). */
+/** Oldest records are dropped beyond this many matches. */
 export const MAX_RECORDS = 1000;
-/** How many games the page's 最近对局 list shows. */
-export const RECENT_SHOW = 20;
+/** The newest records that keep their full rows (lineups, bonds, teammates) — what the settlement replay reads. */
+export const FULL_KEEP = 30;
+/** Budget of the stored JSON in characters (a character costs up to 2 bytes of the browser's ~5 MB quota): the oldest records go first. */
+export const MAX_CHARS = 800_000;
+/** Largest export file the page reads. */
+export const IMPORT_MAX_CHARS = 8_000_000;
 
 const FULL_KEY = `sp.pref.${STATS_PREF_KEY}`;
+const DAMAGED_KEY = `${FULL_KEY}.damaged`;
 
 /** @returns {{ v: number, records: Array }} a fresh empty envelope */
 export const emptyStats = () => ({ v: STATS_VERSION, records: [] });
@@ -38,18 +59,32 @@ const isObj = (v) => !!v && typeof v === 'object' && !Array.isArray(v);
 const int = (v, d) => (Number.isFinite(v) ? Math.round(v) : d);
 const num = (v) => (Number.isFinite(v) ? v : null);
 const bool = (v, d = false) => (typeof v === 'boolean' ? v : d);
-const str = (v) => (typeof v === 'string' && v.length ? v : null);
+/** A non-empty string, cut to `max` characters. */
+const str = (v, max = 64) => (typeof v === 'string' && v.length ? v.slice(0, max) : null);
+
+// per-record bounds (an imported file is foreign data: nothing a row holds may grow without limit)
+const MAX_PLAYERS = 6; // the game seats 4
+const MAX_LINEUP = 12;
+const MAX_ITEMS = 4;
+const MAX_BONDS = 24;
+const MAX_STAT_KEYS = 24;
+const MAX_NAME = 24;
 
 /**
- * Copy only the finite numeric keys of a stats block (the settlement's numbers; unknown numeric fields are
- * kept too — display can lag, data must not).
+ * Copy only the finite numeric keys of a stats block (the settlement's numbers; a numeric field this build does not
+ * know is kept too, up to MAX_STAT_KEYS — display can lag, data should not).
  * @param {any} raw
  * @returns {Record<string, number>}
  */
 function normalizeStatBlock(raw) {
   const out = {};
   if (!isObj(raw)) return out;
-  for (const [k, v] of Object.entries(raw)) if (Number.isFinite(v)) out[k] = v;
+  let n = 0;
+  for (const [k, v] of Object.entries(raw)) {
+    if (!Number.isFinite(v) || k.length > 32) continue;
+    out[k] = v;
+    if (++n >= MAX_STAT_KEYS) break;
+  }
   return out;
 }
 
@@ -82,33 +117,42 @@ export function recordId(res, myId) {
 }
 
 /**
- * Normalize ONE player row: known fields defaulted, unknown fields preserved (forward compat).
+ * Normalize ONE player row: known fields defaulted and bounded, unknown fields dropped. `quit`: the record is a quit
+ * record, whose row may not know its rounds (`roundsPassed: null`).
  * @param {any} raw
+ * @param {boolean} [quit]
  * @returns {any}
  */
-function normalizePlayerRow(raw) {
+function normalizePlayerRow(raw, quit = false) {
   const p = isObj(raw) ? raw : {};
-  const title = isObj(p.title)
-    ? { id: str(p.title.id) || '', name: str(p.title.name) || '', picId: str(p.title.picId) || '', text: str(p.title.text) || '' }
-    : null;
-  const lineup = (Array.isArray(p.lineup) ? p.lineup : []).filter(isObj).slice(0, 12).map((u) => ({
-    // ids only — the tile position (row/col) is replay detail, not a statistic; items kept (配发装备统计)
-    id: str(u.id) || '', golden: bool(u.golden), tier: int(u.tier, 0),
-    items: (Array.isArray(u.items) ? u.items : []).filter((i) => typeof i === 'string' && i.length),
-  })).filter((u) => u.id);
-  const bonds = (Array.isArray(p.bonds) ? p.bonds : []).filter(isObj).map((b) => ({
+  // the page and the replay read the title record from the game data by id: the sent texts are not kept
+  const title = isObj(p.title) && str(p.title.id) ? { id: str(p.title.id) } : null;
+  const lineup = (Array.isArray(p.lineup) ? p.lineup : []).filter(isObj).slice(0, MAX_LINEUP).map((u) => {
+    // ids only — the tile position (row/col) is replay detail, not a statistic; items kept (配发装备统计); a 自选
+    // pick and a 补位 stand-in kept too, or the replayed card would draw the plain operator
+    const e = {
+      id: str(u.id) || '', golden: bool(u.golden), tier: int(u.tier, 0),
+      items: (Array.isArray(u.items) ? u.items : []).filter((i) => typeof i === 'string' && i.length).slice(0, MAX_ITEMS).map((i) => i.slice(0, 64)),
+    };
+    if (u.kind === 'token') e.kind = 'token';
+    if (isObj(u.diy) && str(u.diy.charId)) {
+      e.diy = { charId: str(u.diy.charId), skillIndex: Number.isInteger(u.diy.skillIndex) ? u.diy.skillIndex : 0, uniEquipId: str(u.diy.uniEquipId) };
+    }
+    if (str(u.standInFor)) e.standInFor = str(u.standInFor);
+    return e;
+  }).filter((u) => u.id);
+  const bonds = (Array.isArray(p.bonds) ? p.bonds : []).filter(isObj).slice(0, MAX_BONDS).map((b) => ({
     bondId: str(b.bondId) || str(b.id) || '', layers: int(b.layers, 0), active: bool(b.active),
   })).filter((b) => b.bondId);
   return {
-    ...p, // unknown / future fields pass through untouched
     playerId: str(p.playerId) || '',
     seat: int(p.seat, 0),
-    name: str(p.name) || t('博士'),
+    name: str(p.name, MAX_NAME) || '',
     isBot: bool(p.isBot),
     left: bool(p.left),
     alive: bool(p.alive, true),
     victory: bool(p.victory), // server semantics: team won AND this player was still in at the end
-    roundsPassed: int(p.roundsPassed, 0),
+    roundsPassed: quit ? num(p.roundsPassed) : int(p.roundsPassed, 0),
     eliminatedRound: num(p.eliminatedRound),
     lp: num(p.lp),
     bandId: str(p.bandId),
@@ -122,27 +166,32 @@ function normalizePlayerRow(raw) {
 }
 
 /**
- * Normalize ONE match record to the current shape. Missing fields get defaults; unknown fields (a newer
- * writer's additions) survive untouched, so import → export does not lose them.
+ * Normalize ONE match record to the current shape (a strict schema: missing fields get defaults, unknown ones are
+ * dropped, every string / list is bounded). A record without an `end` is a settled one — the PR #323 build, which
+ * never recorded anything else, wrote none.
  * @param {any} raw
- * @returns {any|null} null when the row is not salvageable (no players array at all)
+ * @returns {any|null} null when the row is not salvageable (no usable player row at all)
  */
 export function normalizeRecord(raw) {
   const r = isObj(raw) ? raw : {};
-  // same rule as buildRecord: a record IS a played match — no usable players array, no record
-  if (!Array.isArray(r.players) || !r.players.length) return null;
-  const base = {
-    id: str(r.id) || '',
+  // a record IS a played match — no usable players array, no record
+  if (!Array.isArray(r.players)) return null;
+  const quit = r.end === 'quit';
+  const players = r.players.filter(isObj).slice(0, MAX_PLAYERS).map((p) => normalizePlayerRow(p, quit));
+  if (!players.length) return null;
+  const rec = {
+    id: str(r.id),
     v: STATS_VERSION,
     t: int(r.t, 0),
+    end: quit ? 'quit' : 'settled',
     victory: bool(r.victory),
-    roundsPassed: int(r.roundsPassed, 0),
+    roundsPassed: quit ? num(r.roundsPassed) : int(r.roundsPassed, 0),
     lastRound: num(r.lastRound),
     hiddenReached: bool(r.hiddenReached),
     hiddenCleared: bool(r.hiddenCleared),
-    reason: str(r.reason),
+    reason: str(r.reason, 32),
     modeId: str(r.modeId),
-    difficulty: str(r.difficulty),
+    difficulty: str(r.difficulty, 24),
     stageId: str(r.stageId),
     bossId: str(r.bossId),
     hiddenBossId: str(r.hiddenBossId),
@@ -151,9 +200,12 @@ export function normalizeRecord(raw) {
     teamLp: num(r.teamLp),
     roomMode: r.roomMode === 'solo' || r.roomMode === 'coop' ? r.roomMode : null,
     selfId: str(r.selfId),
-    players: r.players.filter(isObj).map(normalizePlayerRow),
+    players,
   };
-  return { ...r, ...base };
+  if (r.compact === true) rec.compact = true;
+  // an id-less (hand-made) record gets a content id, so both copies of it land on the same key
+  if (!rec.id) rec.id = `c.${fnv1a(JSON.stringify(rec))}`;
+  return rec;
 }
 
 /**
@@ -164,18 +216,22 @@ export function normalizeRecord(raw) {
  */
 export const MIGRATIONS = {};
 
+/** Newest first (the stored order): by time, then id. */
+const newestFirst = (a, b) => (b.t - a.t) || (a.id < b.id ? -1 : a.id > b.id ? 1 : 0);
+
 /**
  * Bring any stored / imported envelope to the current version.
  * @param {any} raw
- * @returns {{ stats: { v: number, records: any[] }, changed: boolean, newer: boolean }}
+ * @returns {{ stats: { v: number, records: any[] }, changed: boolean, newer: boolean, dropped: number }}
  *   `newer` = the data was written by a NEWER build: returned untouched, callers must not save over it.
+ *   `dropped` = rows that were not salvageable, repeated a record or went beyond MAX_RECORDS: gone from `stats`.
  */
 export function migrateStats(raw) {
-  if (!isObj(raw) || !Array.isArray(raw.records)) return { stats: emptyStats(), changed: false, newer: false };
+  if (!isObj(raw) || !Array.isArray(raw.records)) return { stats: emptyStats(), changed: false, newer: false, dropped: 0 };
   if ((raw.v ?? 0) > STATS_VERSION) {
-    return { stats: { v: raw.v, records: raw.records }, changed: false, newer: true };
+    return { stats: { v: raw.v, records: raw.records }, changed: false, newer: true, dropped: 0 };
   }
-  let v = raw.v ?? 0;
+  let v = Number.isFinite(raw.v) ? raw.v : 0;
   let records = raw.records;
   let changed = v !== STATS_VERSION;
   while (v < STATS_VERSION) {
@@ -183,48 +239,108 @@ export function migrateStats(raw) {
     if (typeof step === 'function') records = step({ v, records }).records;
     v++;
   }
+  // a hand-edited / merged list can be oversized, unsorted or repeat a record: only the newest MAX_RECORDS survive, newest first
   const normalized = [];
+  const seen = new Set(); // a record listed twice (hand-merged data) counts once: the first copy
   for (const r of records) {
     const rec = normalizeRecord(r);
-    if (rec) normalized.push(rec);
+    if (rec && !seen.has(rec.id)) { seen.add(rec.id); normalized.push(rec); }
   }
-  changed ||= normalized.length !== records.length;
-  return { stats: { v: STATS_VERSION, records: normalized }, changed, newer: false };
+  normalized.sort(newestFirst);
+  const kept = normalized.slice(0, MAX_RECORDS);
+  const dropped = records.length - kept.length;
+  // storage is rewritten (self-healed) when a row went, the order changed or an id-less row got its content id
+  changed ||= dropped > 0 || kept.some((rec, i) => !isObj(records[i]) || rec.id !== records[i].id);
+  return { stats: { v: STATS_VERSION, records: kept }, changed, newer: false, dropped };
+}
+
+/** Read the raw stored string (null when absent or unreadable). */
+function readRaw() {
+  try { return globalThis.localStorage?.getItem(FULL_KEY) ?? null; } catch { return null; }
 }
 
 /**
- * Read + migrate the persisted envelope; self-heals older shapes back to storage.
- * @returns {{ v: number, records: any[], newer: boolean }}
+ * Read + migrate the persisted envelope; self-heals older shapes back to storage. An unreadable value (not JSON, or
+ * not an envelope) is moved to `sp.pref.stats.damaged` — kept for a manual recovery — and the history starts again.
+ * @returns {{ v: number, records: any[], newer: boolean, dropped: number, damaged: boolean }}
  */
 export function loadStats() {
-  const { stats, changed, newer } = migrateStats(loadPref(STATS_PREF_KEY, null));
+  const raw = readRaw();
+  if (raw == null) return { ...emptyStats(), newer: false, dropped: 0, damaged: false };
+  let parsed;
+  try { parsed = JSON.parse(raw); } catch { parsed = undefined; }
+  if (!isObj(parsed) || !Array.isArray(parsed.records)) {
+    // keep the bad value where a person can find it; if even that write fails the next save simply replaces it
+    try { globalThis.localStorage?.setItem(DAMAGED_KEY, raw); globalThis.localStorage?.removeItem(FULL_KEY); } catch { /* keep it in place */ }
+    return { ...emptyStats(), newer: false, dropped: 0, damaged: true };
+  }
+  const { stats, changed, newer, dropped } = migrateStats(parsed);
   if (!newer && changed) saveStats(stats);
-  return { ...stats, newer };
+  return { ...stats, newer, dropped, damaged: false };
+}
+
+// ---- compaction + the storage budget ---------------------------------------------------------------------------
+
+const COMPACT_FRAME = ['id', 'v', 't', 'end', 'victory', 'roundsPassed', 'lastRound', 'hiddenReached', 'hiddenCleared', 'reason', 'modeId',
+  'difficulty', 'roomMode', 'durationMs', 'selfId'];
+
+/**
+ * The compact form of a record: the frame and the player's OWN row without lineup, bonds and name — everything the
+ * aggregates and the history list read, nothing a replay needs. Teammates are gone. Idempotent.
+ * @param {any} rec a normalized record
+ * @returns {any}
+ */
+export function compactRecord(rec) {
+  const self = selfRowOf(rec);
+  const out = {};
+  for (const k of COMPACT_FRAME) if (rec[k] != null) out[k] = rec[k];
+  out.compact = true;
+  out.players = self ? [{
+    playerId: self.playerId, seat: self.seat, alive: self.alive, victory: self.victory, roundsPassed: self.roundsPassed,
+    eliminatedRound: self.eliminatedRound, bandId: self.bandId, title: self.title, left: self.left, stats: self.stats,
+  }] : [];
+  return out;
 }
 
 /**
- * Persist the envelope. savePref swallows quota errors — here losing a record silently would do exactly
- * that, so the write reports failure and shrinks the history (oldest quarter) before retrying.
- * @param {{ v: number, records: any[] }} stats
+ * What goes to storage: the newest FULL_KEEP records as they are, older ones compacted, then the oldest dropped until
+ * the JSON fits `maxChars` (the newest record is always kept).
+ * @param {any[]} records newest first
+ * @param {number} [maxChars]
+ * @returns {any[]}
+ */
+export function fitToBudget(records, maxChars = MAX_CHARS) {
+  const kept = [];
+  let used = 40; // the envelope itself
+  records.slice(0, MAX_RECORDS).forEach((r, i) => {
+    const rec = i < FULL_KEEP ? r : compactRecord(r);
+    const n = JSON.stringify(rec).length + 1;
+    if (kept.length && used + n > maxChars) return;
+    used += n;
+    kept.push(rec);
+  });
+  return kept;
+}
+
+/**
+ * Persist the envelope. Never overwrites an envelope of a newer build. Compacts and trims to the budget first; a write
+ * the browser refuses (quota — other keys share it) is retried with half the history, down to a handful of records.
+ * @param {{ v: number, records: any[], newer?: boolean }} stats
  * @returns {boolean} whether a write stuck
  */
 export function saveStats(stats) {
-  const env = { v: STATS_VERSION, records: stats.records };
-  try {
-    globalThis.localStorage?.setItem(FULL_KEY, JSON.stringify(env));
-    return true;
-  } catch { /* quota — fall through to shrinking */ }
-  let recs = stats.records;
-  // two quarter-shrinks at most; records are newest first, so the tail (oldest) is what goes;
-  // a small history that still does not fit is foreign quota pressure — giving up beats gradually erasing it
-  for (let i = 0; i < 2 && recs.length > 8; i++) {
-    recs = recs.slice(0, recs.length - Math.ceil(recs.length / 4));
+  if (stats.newer) return false;
+  let recs = fitToBudget(stats.records);
+  for (;;) {
     try {
-      globalThis.localStorage?.setItem(FULL_KEY, JSON.stringify({ v: STATS_VERSION, records: recs }));
+      const ls = globalThis.localStorage;
+      if (!ls) return false; // no storage at all (disabled by the browser)
+      ls.setItem(FULL_KEY, JSON.stringify({ v: STATS_VERSION, records: recs }));
       return true;
-    } catch { /* keep shrinking */ }
+    } catch { /* quota or storage disabled — fall through to shrinking */ }
+    if (recs.length <= 8) return false; // a small history that still does not fit is foreign quota pressure
+    recs = recs.slice(0, Math.max(8, Math.ceil(recs.length / 2)));
   }
-  return false;
 }
 
 /**
@@ -242,7 +358,7 @@ export function roomModeOf(modeId, roomMode) {
 }
 
 /**
- * Build one record from a raw m.result payload (+ context). Null when there is nothing to store: payloads
+ * Build one settled record from a raw m.result payload (+ context). Null when there is nothing to store: payloads
  * without players (the error-path settlement) or matches the local player did not take part in (spectator
  * seats get every result pushed too — eliminated players, who ARE in players[], keep recording).
  * @param {any} res raw m.result payload
@@ -255,10 +371,11 @@ export function buildRecord(res, ctx = {}) {
   const myId = str(ctx.myId);
   const selfRow = r.players.find((p) => isObj(p) && p.playerId === myId);
   if (!selfRow) return null; // spectator / observer: not my match
-  const rec = normalizeRecord({
+  return normalizeRecord({
     v: STATS_VERSION,
     t: int(ctx.now, 0),
     id: recordId(r, myId),
+    end: 'settled',
     victory: bool(r.victory),
     roundsPassed: int(r.roundsPassed, 0),
     lastRound: num(r.lastRound),
@@ -277,21 +394,120 @@ export function buildRecord(res, ctx = {}) {
     selfId: myId,
     players: r.players,
   });
-  return rec;
+}
+
+// ---- the match left early ----------------------------------------------------------------------------------------
+
+/**
+ * What the page remembers of the match on screen, so that giving it up can still be recorded: when the page first saw
+ * it, whether that was at the start (a duration is only kept then), and the last round the player was seen alive in
+ * (the server tells the others at the settlement, a leaver nothing).
+ * @returns {{ active: boolean, startedAt: number, sawStart: boolean, aliveRound: number|null }}
+ */
+export const createLiveMatch = () => ({ active: false, startedAt: 0, sawStart: false, aliveRound: null });
+
+/** The module's own tracker (fed by installStatsRecorder, read by recordQuit). */
+export const liveMatch = createLiveMatch();
+
+/**
+ * Feed the tracker one app state (cheap: called on every store change).
+ * @param {ReturnType<typeof createLiveMatch>} live
+ * @param {any} state the app store state
+ * @param {number} [now]
+ */
+export function observeMatch(live, state, now = Date.now()) {
+  const pub = state?.match?.public;
+  const inMatch = !!pub && !!pub.phase && pub.phase !== PHASE.LOBBY && pub.phase !== PHASE.RESULT && !state.match.result;
+  if (!inMatch) { live.active = false; return live; }
+  const round = Number(pub.round) || 0;
+  if (!live.active) {
+    live.active = true;
+    live.startedAt = now;
+    live.sawStart = round <= 1;
+    live.aliveRound = null;
+  }
+  const me = Array.isArray(pub.players) ? pub.players.find((p) => isObj(p) && p.playerId === state.me?.playerId) : null;
+  if (me && me.alive !== false) live.aliveRound = Math.max(live.aliveRound ?? 0, round);
+  return live;
+}
+
+/** Start following the store (main.js). Returns the unsubscribe function. */
+export function installStatsRecorder(store) {
+  observeMatch(liveMatch, store.get());
+  return store.subscribe((s) => observeMatch(liveMatch, s));
 }
 
 /**
- * The m.result-shaped payload behind a record — the inverse of buildRecord. The stats page's 最近对局
- * rows hand this to the settlement screen (screens/result.js reads store.match.result through
- * normalizeResult): a finished match can be RE-VIEWED because the record kept every field the payload
- * had. Whatever a record never stored (older / hand-made rows) is simply absent and normalizeResult
- * defaults it, exactly like a tolerant live payload.
+ * The rounds a player who leaves in `phase` of `round` has cleared — the server's rule for a quit (platform.js _quit:
+ * eliminated in round k ⇒ k − 1 passed; leaving in the settlement of round k counts k).
+ * @param {string} phase @param {number} round
+ */
+export function clearedRounds(phase, round) {
+  const r = Number.isFinite(round) ? round : 0;
+  return Math.max(0, phase === PHASE.SETTLE ? r : r - 1);
+}
+
+/**
+ * Build the quit record of a match the local player is leaving (放弃模拟), from the app state and the tracker. Null when
+ * there is nothing of mine to record: no match on screen, its settlement already here (that one is recorded by
+ * recordResult), a spectator seat, or a match the page never saw.
+ * @param {any} state the app store state BEFORE the match is cleared
+ * @param {{ live?: ReturnType<typeof createLiveMatch>, now?: number }} [ctx]
+ * @returns {any|null}
+ */
+export function buildQuitRecord(state, ctx = {}) {
+  const live = ctx.live ?? liveMatch;
+  const now = int(ctx.now, Date.now());
+  const pub = state?.match?.public;
+  const myId = str(state?.me?.playerId);
+  if (!pub || !myId || state.match.result || !live.active) return null;
+  const row = Array.isArray(pub.players) ? pub.players.find((p) => isObj(p) && p.playerId === myId) : null;
+  if (!row) return null; // a spectator seat is no player of the match
+  const alive = row.alive !== false;
+  const round = Number(pub.round) || 0;
+  // alive: the rounds cleared so far; already eliminated: the round it was seen alive in, less one (unknown when the
+  // page never saw it alive — a reload after the elimination)
+  const roundsPassed = alive ? clearedRounds(pub.phase, round) : (live.aliveRound != null ? Math.max(0, live.aliveRound - 1) : null);
+  return normalizeRecord({
+    v: STATS_VERSION,
+    t: now,
+    id: `q.${fnv1a([myId, live.startedAt, pub.modeId ?? '-', state.room?.code ?? '-'].join('|'))}`,
+    end: 'quit',
+    victory: false,
+    roundsPassed,
+    lastRound: num(pub.lastRound),
+    hiddenReached: pub.phase === PHASE.HIDDEN_CORE,
+    hiddenCleared: false,
+    reason: 'quit',
+    modeId: str(pub.modeId),
+    difficulty: str(pub.difficulty),
+    stageId: str(pub.stageId),
+    bossId: str(pub.bossId),
+    hiddenBossId: str(pub.hiddenBossId),
+    seed: null,
+    durationMs: live.sawStart ? Math.max(0, now - live.startedAt) : null,
+    teamLp: num(pub.teamLp),
+    roomMode: roomModeOf(str(pub.modeId), state.room?.mode),
+    selfId: myId,
+    players: [{
+      playerId: myId, seat: row.seat, name: row.name, isBot: false, left: true, alive, victory: false, roundsPassed,
+      eliminatedRound: alive ? null : live.aliveRound, lp: row.lp, bandId: row.bandId,
+    }],
+  });
+}
+
+/**
+ * The m.result-shaped payload behind a settled record — the inverse of buildRecord. The stats page's history
+ * rows hand this to the settlement view (screens/result.js reads it through normalizeResult): a finished match can be
+ * RE-VIEWED because the record kept every field the payload had. Whatever a record never stored is simply absent and
+ * normalizeResult defaults it, exactly like a tolerant live payload. A quit record (nothing was settled) and a
+ * compacted one (its rows are gone) have no settlement to show.
  * @param {any} rec
- * @returns {any|null} null when the row is not a usable record
+ * @returns {any|null} null when the row is not a usable, full, settled record
  */
 export function recordToResult(rec) {
   const r = normalizeRecord(rec);
-  if (!r) return null;
+  if (!r || r.end === 'quit' || r.compact) return null;
   const res = {
     victory: r.victory,
     roundsPassed: r.roundsPassed,
@@ -324,6 +540,16 @@ export function appendRecord(stats, record) {
   return { stats: { v: STATS_VERSION, records }, added: true };
 }
 
+/** load → append → save of one built record (never over an envelope of a newer build). @returns {any|null} the record when stored */
+function storeRecord(rec) {
+  if (!rec) return null;
+  const stats = loadStats();
+  if (stats.newer) return null;
+  const { stats: next, added } = appendRecord(stats, rec);
+  if (added && !saveStats(next)) console.warn('[stats] localStorage write failed (quota?), record not persisted');
+  return added ? rec : null;
+}
+
 /**
  * Record a finished match end-to-end (load → append → save). Returns the built record, or null when
  * nothing was stored (no players / not my match / replay).
@@ -332,16 +558,24 @@ export function appendRecord(stats, record) {
  * @returns {any|null}
  */
 export function recordResult(res, ctx = {}) {
-  const rec = buildRecord(res, ctx);
-  if (!rec) return null;
-  const stats = loadStats();
-  const { stats: next, added } = appendRecord(stats, rec);
-  if (added && !saveStats(next)) console.warn('[stats] localStorage write failed (quota?), record not persisted');
-  return added ? rec : null;
+  return storeRecord(buildRecord(res, ctx));
 }
 
 /**
- * Merge two envelopes (import into existing): union by record id, chronological, capped.
+ * Record the match the player is giving up (放弃模拟), before the app clears its state. Returns the record, or null.
+ * @param {any} state the app store state before the match is cleared
+ * @param {{ live?: ReturnType<typeof createLiveMatch>, now?: number }} [ctx]
+ * @returns {any|null}
+ */
+export function recordQuit(state, ctx = {}) {
+  const live = ctx.live ?? liveMatch;
+  const rec = storeRecord(buildQuitRecord(state, ctx));
+  live.active = false; // one record per match
+  return rec;
+}
+
+/**
+ * Merge two envelopes (import into existing): union by record id, newest first, capped.
  * @param {{ records: any[] }} a current (wins ties)
  * @param {{ records: any[] }} b incoming
  * @returns {{ v: number, records: any[] }}
@@ -350,10 +584,9 @@ export function mergeStats(a, b) {
   const byId = new Map();
   for (const r of [...(Array.isArray(b?.records) ? b.records : []), ...(Array.isArray(a?.records) ? a.records : [])]) {
     const rec = normalizeRecord(r);
-    // id-less (hand-made) rows fall back to a CONTENT hash so both copies land on the same key
-    if (rec) byId.set(rec.id || `c.${fnv1a(JSON.stringify(rec))}`, rec);
+    if (rec) byId.set(rec.id, rec);
   }
-  const records = [...byId.values()].sort((x, y) => (x.t - y.t) || (x.id < y.id ? -1 : 1)).slice(-MAX_RECORDS);
+  const records = [...byId.values()].sort(newestFirst).slice(0, MAX_RECORDS);
   return { v: STATS_VERSION, records };
 }
 
@@ -361,18 +594,31 @@ export function mergeStats(a, b) {
  * Parse + migrate + merge an exported / pasted payload into the current data.
  * @param {any} raw parsed JSON of the imported file
  * @param {{ records: any[] }} current current envelope
- * @returns {{ stats: { v: number, records: any[] }, added: number, skipped: number }}
+ * @returns {{ stats: { v: number, records: any[] }, added: number, skipped: number, dropped: number }}
+ *   added = records new to this device; skipped = duplicates of records it has; dropped = rows of the file that could
+ *   not be read
  */
 export function importStats(raw, current) {
-  const { stats: incoming, newer } = migrateStats(raw);
+  if (isObj(raw) && raw.kind != null && raw.kind !== 'local-stats') {
+    const err = new Error('not a stats export'); // the page shows its own text
+    err.code = 'stats-bad-file';
+    throw err;
+  }
+  if (!isObj(raw) || !Array.isArray(raw.records)) {
+    const err = new Error('not a stats export');
+    err.code = 'stats-bad-file';
+    throw err;
+  }
+  const { stats: incoming, newer, dropped } = migrateStats(raw);
   if (newer) {
-    const err = new Error('该文件由更新版本的客户端导出，请先升级后再导入');
+    const err = new Error('exported by a newer client'); // the page shows its own text
     err.code = 'stats-newer-version';
     throw err;
   }
+  const have = new Set((Array.isArray(current?.records) ? current.records : []).map((r) => r.id));
   const merged = mergeStats(current, incoming);
-  const added = merged.records.length - (Array.isArray(current?.records) ? current.records.length : 0);
-  return { stats: merged, added: Math.max(0, added), skipped: incoming.records.length - Math.max(0, added) };
+  const added = incoming.records.filter((r) => !have.has(r.id)).length;
+  return { stats: merged, added, skipped: incoming.records.length - added, dropped };
 }
 
 /**
@@ -386,11 +632,11 @@ export function exportStats(stats) {
     kind: 'local-stats',
     v: STATS_VERSION,
     exportedAt: new Date().toISOString(),
-    records: Array.isArray(stats?.records) ? stats.records : [],
+    records: fitToBudget(Array.isArray(stats?.records) ? stats.records : []),
   };
 }
 
-// ---- aggregation (what the page shows; records may hold more than any view uses) ------------------------
+// ---- aggregation (what the page shows; records may hold more than any view uses) ------------------------------------
 
 const SELF_STATS = ['dmgDealt', 'kills', 'bossDamage', 'activatedLayers', 'merges', 'itemsEquipped', 'gold', 'perfectRounds', 'refreshes', 'leaks', 'lpLost'];
 
@@ -412,15 +658,43 @@ export function selfRowOf(rec) {
 const selfWon = (rec, self) => (self ? !!self.victory : !!rec.victory);
 
 /**
- * Aggregate records for the stats page. Everything is keyed by ids (bandId / titleId / difficulty); the
- * page maps them to names and icons through the game data.
+ * The rounds the player passed in a record: its own row's (the table the settlement prints per player), else the
+ * team's; 0 when the record does not know.
+ * @param {any} rec
+ */
+export function roundsOf(rec) {
+  const self = selfRowOf(rec);
+  const v = self && Number.isFinite(self.roundsPassed) ? self.roundsPassed : rec?.roundsPassed;
+  return Number.isFinite(v) ? v : 0;
+}
+
+/**
+ * Whether a record enters the aggregates (see the header). A settled record always does. A quit record does once the
+ * player had finished at least one battle: cleared a round, or was already eliminated; a match given up before that —
+ * entered and left right away — is history only.
+ * @param {any} rec a normalized record
+ * @returns {boolean}
+ */
+export function countsTowardStats(rec) {
+  if (!isObj(rec)) return false;
+  if (rec.end !== 'quit') return true;
+  const self = selfRowOf(rec);
+  if (!self) return false;
+  return self.alive === false || (Number.isFinite(self.roundsPassed) && self.roundsPassed >= 1);
+}
+
+/**
+ * Aggregate records for the stats page — over the records that count; `total` / `excluded` say how many did not.
+ * Everything is keyed by ids (bandId / titleId / difficulty); the page maps them to names and icons through the game
+ * data. The combat totals read the settled records' stat blocks (a quit record has none).
  * @param {any[]} records
  * @returns {any}
  */
 export function aggregateStats(records) {
-  const rs = Array.isArray(records) ? records : [];
+  const all = Array.isArray(records) ? records : [];
+  const rs = all.filter(countsTowardStats);
   const out = {
-    count: rs.length, wins: 0,
+    total: all.length, count: rs.length, excluded: all.length - rs.length, wins: 0,
     rounds: { total: 0, max: 0 },
     duration: { totalMs: 0 },
     hidden: { reached: 0, cleared: 0 },
@@ -431,13 +705,14 @@ export function aggregateStats(records) {
     const self = selfRowOf(rec);
     const won = selfWon(rec, self);
     if (won) out.wins++;
-    out.rounds.total += int(rec.roundsPassed, 0);
-    out.rounds.max = Math.max(out.rounds.max, int(rec.roundsPassed, 0));
+    const rounds = roundsOf(rec);
+    out.rounds.total += rounds;
+    out.rounds.max = Math.max(out.rounds.max, rounds);
     out.duration.totalMs += num(rec.durationMs) || 0;
     if (rec.hiddenReached) out.hidden.reached++;
     if (rec.hiddenCleared) out.hidden.cleared++;
 
-    const d = rec.difficulty || t('未知');
+    const d = rec.difficulty || 'UNKNOWN';
     const bd = (out.byDifficulty[d] ||= { games: 0, wins: 0, hiddenCleared: 0 });
     bd.games++;
     if (won) bd.wins++;
@@ -458,7 +733,7 @@ export function aggregateStats(records) {
       if (won) b.wins++;
     }
 
-    if (self && isObj(self.stats)) {
+    if (rec.end !== 'quit' && self && isObj(self.stats)) {
       for (const k of SELF_STATS) {
         const v = self.stats[k];
         if (Number.isFinite(v)) out.sums[k] = (out.sums[k] || 0) + v;