feat(python): 完成 Python 全量迁移——剩余平台、登录通道与公共层修复

- 新增 5sing/apple/xm/me/qt/lr 平台包与取流实现（含 xm-sign、MissEvan 签名、蜻蜓 HMAC、Apple developer token）
- 新增 wy/kg/tx/lr 登录：扫码、手机号、账密（kg 20028 风控指纹）、cookie 绑定、kg/tx 续期
- request 层：保留多值 Set-Cookie；JSON body 紧凑化（修复 kg 网关验签）；直连不经系统代理（对齐 Node）
- 登录路由统一 Body(embed=True)，修复扫码轮询 422；lifespan 接入登录续期调度
- ruff/format/pyright 全绿；14 平台真实联网与 HTTP 路由验证通过

app/sdk/platforms/kg/lyric.py

@@ -0,0 +1,91 @@
+"""酷狗歌词（对应 sdk/kg/lyric.ts）。
+
+两步：`lyrics.kugou.com/search` 按歌名+hash+时长找候选 → `lyrics.kugou.com/download`
+取回 base64 内容。`fmt=krc` 需走 krc_decode 解密，`fmt=lrc` 直接 base64 解码。
+"""
+
+from __future__ import annotations
+
+import base64
+from typing import Any
+
+from app.sdk.common.request import http_fetch
+from app.sdk.platforms.kg.krc_decode import decode_krc
+
+HEADERS = {
+    "KG-RC": "1",
+    "KG-THash": "expand_search_manager.cpp:852736169:451",
+    "User-Agent": "KuGou2012-9020-ExpandSearchManager",
+}
+
+
+def get_intv(interval: Any) -> int:
+    """`mm:ss` → 毫秒（原文把秒当毫秒拼给上游，这里保持一致）。"""
+    if not interval:
+        return 0
+    parts = str(interval).split(":")
+    total = 0
+    unit = 1
+    while parts:
+        part = parts.pop()
+        try:
+            total += int(float(part)) * unit
+        except ValueError:
+            pass
+        unit *= 60
+    return int(total)
+
+
+async def _search_lyric(name: str, hash_value: str, time: Any, try_num: int = 0) -> dict[str, str] | None:
+    from app.sdk.platforms.kg.util import encode_uri_component
+
+    url = (
+        "http://lyrics.kugou.com/search?ver=1&man=yes&client=pc"
+        f"&keyword={encode_uri_component(name)}&hash={hash_value}&timelength={time}&lrctxt=1"
+    )
+    resp = await http_fetch(url, headers=HEADERS)
+    if resp.status_code != 200:
+        if try_num > 5:
+            raise RuntimeError("歌词获取失败")
+        return await _search_lyric(name, hash_value, time, try_num + 1)
+    body = resp.body if isinstance(resp.body, dict) else {}
+    candidates = body.get("candidates") or []
+    if not candidates:
+        return None
+    info = candidates[0]
+    fmt = "krc" if info.get("krctype") == 1 and info.get("contenttype") != 1 else "lrc"
+    return {"id": str(info.get("id")), "accessKey": str(info.get("accesskey")), "fmt": fmt}
+
+
+async def _get_lyric_download(id: str, access_key: str, fmt: str, try_num: int = 0) -> dict[str, str]:
+    url = f"http://lyrics.kugou.com/download?ver=1&client=pc&id={id}&accesskey={access_key}&fmt={fmt}&charset=utf8"
+    resp = await http_fetch(url, headers=HEADERS)
+    if resp.status_code != 200:
+        if try_num > 5:
+            raise RuntimeError("歌词获取失败")
+        # 重试必须回到本方法（搜索接口与下载接口的入参语义不同）
+        return await _get_lyric_download(id, access_key, fmt, try_num + 1)
+    body = resp.body if isinstance(resp.body, dict) else {}
+    content = str(body.get("content") or "")
+    match body.get("fmt"):
+        case "krc":
+            return await decode_krc(content)
+        case "lrc":
+            return {
+                "lyric": base64.b64decode(content).decode("utf-8", errors="replace"),
+                "tlyric": "",
+                "rlyric": "",
+                "yrc": "",
+            }
+        case _:
+            raise RuntimeError(f"未知歌词格式: {body.get('fmt')}")
+
+
+async def get_lyric(song_info: dict[str, Any]) -> dict[str, str]:
+    name = str(song_info.get("name") or "")
+    hash_value = str(song_info.get("hash") or song_info.get("songmid") or "")
+    time = song_info.get("_interval") or get_intv(song_info.get("interval"))
+    result = await _search_lyric(name, hash_value, time)
+    if not result:
+        raise RuntimeError("Get lyric failed")
+    return await _get_lyric_download(result["id"], result["accessKey"], result["fmt"])