fix: 推送网络请求加重试，避免瞬时失败漏推

mDNS(.local)域名解析基于组播UDP，偶发丢包会导致整轮推送直接抛异常跳过。
_request() 对连接类异常加重试(2次/间隔2s)；画廊清理列表拉取失败也不再
阻塞后续 /upload，清理是锦上添花而非推送必要条件。

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

pusher.py

@@ -6,21 +6,31 @@
 http://<EPD_HOST>/ 调试同一套接口）。
 """
 import json
+import time
 import urllib.parse
 import urllib.request
 import urllib.error
 
 import config
 
+# 局域网 mDNS（.local）域名解析基于组播 UDP，偶发瞬时失败正常，重试即可恢复。
+RETRY_TIMES = 2
+RETRY_DELAY = 2
+
 
 def _request(method, path, headers=None, body=None):
     url = f"http://{config.EPD_HOST}{path}"
     req = urllib.request.Request(url, data=body, headers=headers or {}, method=method)
-    try:
-        with urllib.request.urlopen(req, timeout=30) as resp:
-            return resp.read().decode("utf-8", "ignore")
-    except urllib.error.HTTPError as e:
-        raise RuntimeError(f"HTTP {e.code}: {e.read().decode('utf-8', 'ignore')}") from e
+    for attempt in range(RETRY_TIMES + 1):
+        try:
+            with urllib.request.urlopen(req, timeout=30) as resp:
+                return resp.read().decode("utf-8", "ignore")
+        except urllib.error.HTTPError as e:
+            raise RuntimeError(f"HTTP {e.code}: {e.read().decode('utf-8', 'ignore')}") from e
+        except urllib.error.URLError:
+            if attempt == RETRY_TIMES:
+                raise
+            time.sleep(RETRY_DELAY)
 
 
 def _list_gallery_names():
@@ -29,8 +39,14 @@ def _list_gallery_names():
 
 
 def _clear_gallery():
-    """设备画廊按追加保存，用完即删，使其始终只留最新一张。单张删除失败不影响后续上传。"""
-    for name in _list_gallery_names():
+    """设备画廊按追加保存，用完即删，使其始终只留最新一张。
+    清理是锦上添花，不是推送的必要条件——拉列表或单张删除失败都不能阻塞后续上传。"""
+    try:
+        names = _list_gallery_names()
+    except Exception as e:
+        print(f"[推送] 拉取画廊列表失败，跳过本次清理：{e}")
+        return
+    for name in names:
         try:
             _request("POST", f"/delete_image?name={urllib.parse.quote(name)}")
         except Exception as e: