Gitee 也做成幂等：已存在就复用 + 先删同名附件

重发时 Gitee 直接 400「该标签已经存在发行版」，
而且拿不到 id，后面的附件也传不上。

改成和 EzHub 一样的流程：
先按标签查已有的（查到就复用 id），复用前删掉同名旧附件，再传。
这样重跑多少次，两边的附件数都稳定。

_build/release_all.py

@@ -99,24 +99,63 @@ def gitee_release(token: str, version: str, body: str,
     api = "https://gitee.com/api/v5/repos/xmz7891/ykxmz"
     tag = "v" + version
 
-    payload = json.dumps({
-        "access_token": token, "tag_name": tag,
-        "name": "ykxmz " + version, "body": body,
-        "target_commitish": "main", "prerelease": False,
-    }).encode("utf-8")
-    req = urllib.request.Request(
-        api + "/releases", data=payload, method="POST",
-        headers={"Content-Type": "application/json;charset=UTF-8",
-                 "User-Agent": "ykxmz-release"})
+    # 先看标签有没有发行版。
+    # 不先查的话，重发会直接 400「该标签已经存在发行版」——
+    # 而且没有可复用的 id，后面的附件也就传不上。
+    rid = None
     try:
-        with urllib.request.urlopen(req, timeout=90) as resp:
-            reply = json.loads(resp.read().decode("utf-8", "replace"))
-        rid = reply.get("id")
-        print("    ✓ 发行版已建 id=%s" % rid)
-    except urllib.error.HTTPError as exc:
-        detail = exc.read().decode("utf-8", "replace")[:300]
-        print("    ✗ 建发行版失败 HTTP %s: %s" % (exc.code, detail))
-        return False
+        with urllib.request.urlopen(
+                "%s/releases/tags/%s?access_token=%s" % (api, tag, token),
+                timeout=60) as resp:
+            rid = json.loads(resp.read().decode("utf-8", "replace")).get("id")
+            print("    • 该标签已有发行版 id=%s，复用" % rid)
+    except urllib.error.HTTPError:
+        pass
+
+    if not rid:
+        payload = json.dumps({
+            "access_token": token, "tag_name": tag,
+            "name": "ykxmz " + version, "body": body,
+            "target_commitish": "main", "prerelease": False,
+        }).encode("utf-8")
+        req = urllib.request.Request(
+            api + "/releases", data=payload, method="POST",
+            headers={"Content-Type": "application/json;charset=UTF-8",
+                     "User-Agent": "ykxmz-release"})
+        try:
+            with urllib.request.urlopen(req, timeout=90) as resp:
+                reply = json.loads(resp.read().decode("utf-8", "replace"))
+            rid = reply.get("id")
+            print("    ✓ 发行版已建 id=%s" % rid)
+        except urllib.error.HTTPError as exc:
+            detail = exc.read().decode("utf-8", "replace")[:300]
+            print("    ✗ 建发行版失败 HTTP %s: %s" % (exc.code, detail))
+            return False
+
+    # 复用已有发行版时先把同名旧附件删掉，否则每跑一次多一份。
+    try:
+        with urllib.request.urlopen(
+                "%s/releases/%s?access_token=%s" % (api, rid, token),
+                timeout=60) as resp:
+            existing = json.loads(resp.read().decode("utf-8", "replace"))
+        wanted = {p.name for p in files}
+        # Gitee 叫 attach_files，Gitea 叫 assets
+        old_assets = (existing.get("assets")
+                      or existing.get("attach_files") or [])
+        for asset in old_assets:
+            name = asset.get("name") or asset.get("filename")
+            aid = asset.get("id")
+            if name in wanted and aid:
+                del_url = ("%s/releases/%s/attach_files/%s"
+                           "?access_token=%s" % (api, rid, aid, token))
+                dreq = urllib.request.Request(del_url, method="DELETE")
+                try:
+                    urllib.request.urlopen(dreq, timeout=60)
+                    print("    • 删掉同名旧附件 %s" % name)
+                except urllib.error.HTTPError as exc:
+                    print("    • 删 %s 失败 HTTP %s（继续）" % (name, exc.code))
+    except Exception as exc:                           # noqa: BLE001
+        print("    • 清理旧附件时出错（继续）: %s" % exc)
 
     ok = 0
     for path in files: