feat(bot): !play id <id> 与其他命令语法保持一致

按 id 精确播放原本要写 `!play id:<id>`，冒号在一堆 `!<命令> <子命令> <参数>`
的命令里显得很突兀。现在空格写法 `!play id <id>` 也可以，`!add` / `!playnext`
共用同一个解析器，一起生效。

`id:<id>` 继续支持，不做废弃：用户的聊天记录、旧文档和 !search 输出里都是
这个写法。

冒号是个明确的标记，所以 `id:<任意内容>` 一律当 id。空格不是——「ID 4」和
「ID Bruno」都是真实存在的歌名，而且 `id <链接>` 原本会落到 URL 分支正常解析。
所以空格写法只认「长得像 id」的 token（纯数字 / BV 号 / 11 位以上的 id 字符），
其余照旧继续走 URL 识别，最后落到普通搜索，不会把搜索词误当成 id。

同步更新 !search 输出的提示、三条 Usage、!help 和 README。

Closes #139

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

src/bot/instance.ts

@@ -1113,9 +1113,9 @@ export class BotInstance extends EventEmitter {
   /**
    * Resolve a !play/!add/!playnext argument into a single Song, supporting three
    * forms (issue #90):
-   *   1) "#N"          — the Nth result of the previous !search
-   *   2) id:<id> / URL — an exact song (disambiguates same-name songs)
-   *   3) plain text    — search, returning the single most-popular hit (legacy)
+   *   1) "#N"           — the Nth result of the previous !search
+   *   2) id <id> / URL  — an exact song (disambiguates same-name songs)
+   *   3) plain text     — search, returning the single most-popular hit (legacy)
    */
   private async resolvePlayQuery(cmd: ParsedCommand): Promise<{ song?: Song; error?: string }> {
     const args = (cmd.args ?? "").trim();
@@ -1131,7 +1131,7 @@ export class BotInstance extends EventEmitter {
       return { song: this.lastSearchResults[sel - 1] };
     }
 
-    // 2) id:/URL — fetch that exact song.
+    // 2) id/URL — fetch that exact song.
     const ref = parseSongRef(args);
     if (ref) {
       if (ref.platform) this.assertProviderEnabled(ref.platform);
@@ -1159,13 +1159,13 @@ export class BotInstance extends EventEmitter {
       (s, i) => `${i + 1}. ${s.name} - ${s.artist}${s.album ? ` 《${s.album}》` : ""} [id:${s.id}]`,
     );
     return [
-      `搜索结果（用 ${p}play #序号 播放，或 ${p}play id:<id>）:`,
+      `搜索结果（用 ${p}play #序号 播放，或 ${p}play id <id>）:`,
       ...lines,
     ].join("\n");
   }
 
   private async cmdPlay(cmd: ParsedCommand, requesterName?: string): Promise<string> {
-    if (!cmd.args) return `Usage: ${this.config.commandPrefix}play <song name | #N | id:<id> | URL>`;
+    if (!cmd.args) return `Usage: ${this.config.commandPrefix}play <song name | #N | id <id> | URL>`;
     const { song, error } = await this.resolvePlayQuery(cmd);
     if (error) return error;
     const song0 = song!;
@@ -1259,7 +1259,7 @@ export class BotInstance extends EventEmitter {
   }
 
   private async cmdAdd(cmd: ParsedCommand, requesterName?: string): Promise<string> {
-    if (!cmd.args) return `Usage: ${this.config.commandPrefix}add <song name | #N | id:<id> | URL>`;
+    if (!cmd.args) return `Usage: ${this.config.commandPrefix}add <song name | #N | id <id> | URL>`;
     const { song, error } = await this.resolvePlayQuery(cmd);
     if (error) return error;
     const s = song!;
@@ -1283,7 +1283,7 @@ export class BotInstance extends EventEmitter {
   }
 
   private async cmdPlayNext(cmd: ParsedCommand, requesterName?: string): Promise<string> {
-    if (!cmd.args) return `Usage: ${this.config.commandPrefix}playnext <song name | #N | id:<id> | URL>`;
+    if (!cmd.args) return `Usage: ${this.config.commandPrefix}playnext <song name | #N | id <id> | URL>`;
     const { song, error } = await this.resolvePlayQuery(cmd);
     if (error) return error;
     const s = song!;
@@ -1840,8 +1840,8 @@ export class BotInstance extends EventEmitter {
       ...(flagHelp ? [`  Source flags: ${flagHelp}`] : []),
       `${p}search <name> — List top matches to pick a specific (same-name) song`,
       `${p}play #N       — Play the Nth result of the last ${p}search`,
-      `${p}play id:<id>  — Play an exact song by id / URL`,
-      `${p}add <song>   — Add to queue (also accepts #N / id: / URL)`,
+      `${p}play id <id> — Play an exact song by id / URL`,
+      `${p}add <song>   — Add to queue (also accepts #N / id <id> / URL)`,
       `${p}playnext <song> — Insert as next song (alias: ${p}pn)`,
       `${p}pause/resume — Pause/resume`,
       `${p}next/prev    — Next/previous`,

src/bot/song-ref.test.ts

@@ -21,6 +21,59 @@ describe("parseSongRef (#90 exact-song selection)", () => {
     expect(parseSongRef("id:185868,")).toEqual({ id: "185868", platform: null });
   });
 
+  // Issue #139: `!play id <id>` matches the "<command> <subcommand> <arg>"
+  // shape of every other command. The colon form stays supported — users have
+  // it in their chat scrollback and in older docs.
+  it("parses the space-separated id form", () => {
+    expect(parseSongRef("id 185868")).toEqual({ id: "185868", platform: null });
+    expect(parseSongRef("ID 004Z8Ihr0JIu5s")).toEqual({ id: "004Z8Ihr0JIu5s", platform: null });
+    expect(parseSongRef("id   185868")).toEqual({ id: "185868", platform: null });
+    expect(parseSongRef("id 185868.")).toEqual({ id: "185868", platform: null });
+  });
+
+  it("does not mistake a word merely starting with 'id' for an id reference", () => {
+    expect(parseSongRef("idol")).toBeNull();
+    expect(parseSongRef("identity 185868")).toBeNull();
+    expect(parseSongRef("id")).toBeNull();
+    expect(parseSongRef("id:")).toBeNull();
+    // Two remaining tokens are a search phrase, not an id.
+    expect(parseSongRef("id die for you")).toBeNull();
+  });
+
+  // Without a colon, "id" is just a word — "ID 4" and "ID Bruno" are real track
+  // titles. The space form therefore only claims tokens that could actually be
+  // an id; everything else stays a search term.
+  it("only treats the space form as an id when the token looks like one", () => {
+    expect(parseSongRef("id Bruno")).toBeNull();
+    expect(parseSongRef("id Marshmello")).toBeNull();
+    expect(parseSongRef("id 4ever")).toBeNull();
+    // …while every real id shape is still accepted.
+    expect(parseSongRef("id 4")).toEqual({ id: "4", platform: null });          // numeric
+    expect(parseSongRef("id BV1yxHQeYEuE")).toEqual({ id: "BV1yxHQeYEuE", platform: null });
+    expect(parseSongRef("id 004Z8Ihr0JIu5s")).toEqual({ id: "004Z8Ihr0JIu5s", platform: null }); // QQ mid
+    expect(parseSongRef("id a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6")).toEqual({
+      id: "a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6",
+      platform: null,
+    }); // Jellyfin GUID / Kugou hash
+  });
+
+  it("keeps the colon form unrestricted, so a short or odd id still works", () => {
+    expect(parseSongRef("id:Bruno")).toEqual({ id: "Bruno", platform: null });
+    expect(parseSongRef("id: 4ever")).toEqual({ id: "4ever", platform: null });
+  });
+
+  it("does not let the space form swallow a pasted URL", () => {
+    // `id <url>` used to fall through to the URL branches; it still must.
+    expect(parseSongRef("id https://music.163.com/song?id=185868")).toEqual({
+      id: "185868",
+      platform: "netease",
+    });
+    expect(parseSongRef("id https://y.qq.com/n/ryqq/songDetail/004Z8Ihr0JIu5s")).toEqual({
+      id: "004Z8Ihr0JIu5s",
+      platform: "qq",
+    });
+  });
+
   it("does NOT treat NetEase collection (playlist/album/artist) URLs as a song id", () => {
     // These reuse ?id= but are not songs — they should fall through to search,
     // not misresolve to getSongDetail(collectionId) and error "no song".

src/bot/song-ref.ts

@@ -18,9 +18,22 @@ export interface SongRef {
   platform: "netease" | "qq" | "bilibili" | null;
 }
 
+/**
+ * Could this token plausibly BE an id on a supported platform?
+ *   - NetEase / Kugou numeric ids      → all digits
+ *   - BiliBili                         → BV + 8-12 alphanumerics
+ *   - QQ mid (14), YouTube (11), Spotify (22), Jellyfin GUID / Kugou hash (32)
+ *                                      → 11+ chars from the id alphabet
+ * Deliberately conservative: anything rejected here just stays an ordinary
+ * search term, which is what it almost certainly was.
+ */
+function looksLikeSongId(token: string): boolean {
+  return /^(?:\d+|BV[0-9A-Za-z]{8,12}|[0-9A-Za-z_-]{11,})$/i.test(token);
+}
+
 /**
  * Detect an explicit song reference in a query. Recognizes:
- *   - `id:<id>`                         → platform from flags/default
+ *   - `id <id>` / `id:<id>`             → platform from flags/default
  *   - NetEase song URL                  → music.163.com/song?id=N (also /#/song?id=N, /song/N)
  *   - QQ song URL                       → y.qq.com/.../songDetail/MID (or ?songmid=MID)
  *   - BiliBili BVID (bare or in a URL)  → bilibili.com/video/BVxxxx, b23.tv, or BVxxxx
@@ -30,11 +43,25 @@ export function parseSongRef(raw: string): SongRef | null {
   const q = (raw ?? "").trim();
   if (!q) return null;
 
-  // Explicit "id:<id>" — platform decided by the command's flags/default.
-  // Strip trailing punctuation that tags along from a chat paste ("id:12345."
-  // / "id:12345)") — no supported id (numeric / BVID / mid) ends in those.
-  const idPrefix = /^id:\s*(\S+)$/i.exec(q);
-  if (idPrefix) return { id: idPrefix[1].replace(/[.,;)\]]+$/, ""), platform: null };
+  // Explicit id — platform decided by the command's flags/default. The
+  // separator is a colon or plain whitespace, so `id <id>` matches the
+  // `!<cmd> <sub> <arg>` shape of every other command (issue #139) while the
+  // older `id:<id>` keeps working. Strip trailing punctuation that tags along
+  // from a chat paste ("id:12345." / "id:12345)") — no supported id
+  // (numeric / BVID / mid) ends in those.
+  //
+  // The colon is an unambiguous sigil, so `id:<anything>` is always an id. A
+  // space is not: "ID 4" and "ID Bruno" are real track titles, and `id <url>`
+  // has to keep resolving as a URL. So the space form only claims tokens that
+  // could actually be an id; anything else falls through to the URL branches
+  // below and ultimately to a plain search.
+  const idPrefix = /^id(:\s*|\s+)(\S+)$/i.exec(q);
+  if (idPrefix) {
+    const id = idPrefix[2].replace(/[.,;)\]]+$/, "");
+    if (idPrefix[1].startsWith(":") || looksLikeSongId(id)) {
+      return { id, platform: null };
+    }
+  }
 
   // BiliBili BV id, bare or inside a bilibili URL (NetEase ids are numeric, so
   // a "BV..." token never collides with them).