feat(domain): pure business logic for parsing, identity, slots, acquisition, paths, organize, download state (W1-2)

- release-parser: title/file/dir parsing with MP parity + deviations (airDate/issue,
  cut, release group suffix fallback, dir+file merge, safe episode offset)
- identity: title normalization (NFKC, trad->simp map, season suffix) and
  evidence-level candidate ranking (year tolerance ±1, no probabilities)
- slot: hard/soft/upgrade evaluation (missing vs unmet fields), state machine,
  movie/unit completion (season pack must be covered by actual file list)
- acquisition: new_title/catch_up/upgrade modes, priority order, budget,
  cache volume hard threshold with resume watermark (no double counting)
- path: immutable path bindings, restricted naming templates, sanitize,
  conflict detection, downloader<->host path mapping
- organize: planOrganize with sidecar pairing, sample exclusion, existing
  target policy, crossDevice marking, H&R -> conflict for move
- download-state: qB state mapping, completion, no-progress evidence

230 tests, ~97% statement coverage.

Co-Authored-By: Claude Fable 5.1 <[email protected]>

packages/domain/src/organize/sidecars.ts

@@ -0,0 +1,82 @@
+/** 附属文件(字幕/外挂音轨)的语言标签,按主干名剥离后与主视频配对 */
+const LANG_TAG: Record<string, "zh-Hans" | "zh-Hant" | "en" | "ja" | "ko" | "flag"> = {
+  chs: "zh-Hans",
+  sc: "zh-Hans",
+  gb: "zh-Hans",
+  chi: "zh-Hans",
+  zho: "zh-Hans",
+  zh: "zh-Hans",
+  "zh-cn": "zh-Hans",
+  "zh-hans": "zh-Hans",
+  "zh-sg": "zh-Hans",
+  简体: "zh-Hans",
+  简中: "zh-Hans",
+  简: "zh-Hans",
+  cht: "zh-Hant",
+  tc: "zh-Hant",
+  big5: "zh-Hant",
+  "zh-tw": "zh-Hant",
+  "zh-hk": "zh-Hant",
+  "zh-hant": "zh-Hant",
+  繁体: "zh-Hant",
+  繁體: "zh-Hant",
+  繁中: "zh-Hant",
+  繁: "zh-Hant",
+  eng: "en",
+  en: "en",
+  english: "en",
+  jpn: "ja",
+  ja: "ja",
+  jp: "ja",
+  kor: "ko",
+  ko: "ko",
+  default: "flag",
+  forced: "flag",
+  sdh: "flag",
+  cc: "flag",
+  简英: "zh-Hans",
+  繁英: "zh-Hant",
+  中英: "zh-Hans",
+  双语: "zh-Hans",
+  简繁: "zh-Hans",
+};
+
+export const basename = (p: string) => p.replace(/\\/g, "/").split("/").pop() ?? p;
+export const dirname = (p: string) => {
+  const s = p.replace(/\\/g, "/");
+  const i = s.lastIndexOf("/");
+  return i <= 0 ? (i === 0 ? "/" : "") : s.slice(0, i);
+};
+export const splitExt = (name: string): [string, string] => {
+  const i = name.lastIndexOf(".");
+  return i > 0 ? [name.slice(0, i), name.slice(i + 1)] : [name, ""];
+};
+
+/** 字幕主干名:去扩展名后逐级剥掉 .chs/.eng/.default 等语言标签,返回小写主干与剥下的标签 */
+export function sidecarStem(name: string): { stem: string; tags: string[] } {
+  let [stem] = splitExt(basename(name));
+  const tags: string[] = [];
+  for (;;) {
+    const i = stem.lastIndexOf(".");
+    if (i <= 0) break;
+    const tag = stem.slice(i + 1).toLowerCase();
+    if (!(tag in LANG_TAG)) break;
+    tags.unshift(tag);
+    stem = stem.slice(0, i);
+  }
+  return { stem: stem.toLowerCase(), tags };
+}
+
+/** 目标字幕后缀(对照 MP:繁体优先判定 → .zh-tw;简体 → .chi.zh-cn;英 → .eng;日 → .ja) */
+export function sidecarLanguageSuffix(tags: readonly string[]): string {
+  const langs = tags.map((t) => LANG_TAG[t]);
+  let s = "";
+  if (langs.includes("zh-Hant")) s = ".zh-tw";
+  else if (langs.includes("zh-Hans")) s = ".chi.zh-cn";
+  else if (langs.includes("en")) s = ".eng";
+  else if (langs.includes("ja")) s = ".ja";
+  else if (langs.includes("ko")) s = ".ko";
+  if (tags.includes("default")) s += ".default";
+  if (tags.includes("forced")) s += ".forced";
+  return s;
+}