feat(identity): weighted evidence table, sequel numbers, generic-name guard (ID-2)

Configurable DEFAULT_MATCH_WEIGHTS; Chinese/English names both count and
corroborate; Chapter/Part/第N章 sequel conflicts reject; missing season
penalised; category words and single-word aliases colliding in the pool
cannot confirm alone; alias-only hits need year or second-script support;
same-level ties broken by exact year then matched name scripts.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

packages/domain/src/identity/sequel.ts

@@ -0,0 +1,60 @@
+/**
+ * 续作 / 章节 / Part 序号(ID-2):`Chapter III`、`Part Two`、`Vol. 2`、`第3章`、`第三章`、`Ⅲ`。
+ * 只认显式关键词或罗马数字符号,不把片名末尾的普通数字当序号(`Blade Runner 2049`、`Apollo 13`)。
+ * 季号不在这里(季由解析器单独给出)。
+ */
+import { cnToInt } from "../release-parser/cn-number.ts";
+
+const WORD_NUM: Record<string, number> = {
+  one: 1,
+  two: 2,
+  three: 3,
+  four: 4,
+  five: 5,
+  six: 6,
+  seven: 7,
+  eight: 8,
+  nine: 9,
+  ten: 10,
+  first: 1,
+  second: 2,
+  third: 3,
+  fourth: 4,
+  final: -1,
+};
+const ROMAN: Record<string, number> = { i: 1, ii: 2, iii: 3, iv: 4, v: 5, vi: 6, vii: 7, viii: 8, ix: 9, x: 10 };
+const ROMAN_CHAR: Record<string, number> = {
+  Ⅰ: 1,
+  Ⅱ: 2,
+  Ⅲ: 3,
+  Ⅳ: 4,
+  Ⅴ: 5,
+  Ⅵ: 6,
+  Ⅶ: 7,
+  Ⅷ: 8,
+  Ⅸ: 9,
+  Ⅹ: 10,
+};
+
+function toNum(tok: string): number | undefined {
+  const t = tok.toLowerCase();
+  if (/^\d{1,2}$/.test(t)) return Number(t);
+  if (t in ROMAN) return ROMAN[t];
+  if (t in WORD_NUM) return WORD_NUM[t]! > 0 ? WORD_NUM[t] : undefined;
+  return undefined;
+}
+
+export function sequelNumbers(title: string): number[] {
+  if (!title) return [];
+  const out = new Set<number>();
+  const s = title.replace(/[ⅠⅡⅢⅣⅤⅥⅦⅧⅨⅩ]/g, (c) => ` ${ROMAN_CHAR[c]} `);
+  for (const m of s.matchAll(/\b(?:chapter|part|vol(?:ume)?)\b\.?\s*[:：-]?\s*([0-9]{1,2}|[ivx]{1,4}|[a-z]+)\b/giu)) {
+    const n = toNum(m[1]!);
+    if (n !== undefined) out.add(n);
+  }
+  for (const m of s.matchAll(/第\s*([0-9]{1,2}|[一二三四五六七八九十]{1,3})\s*章/gu)) {
+    const n = /^\d+$/.test(m[1]!) ? Number(m[1]) : cnToInt(m[1]!);
+    if (n !== undefined) out.add(n);
+  }
+  return [...out];
+}