fix(telegram): back off on transient polling failures

Give getUpdates a wider HTTP timeout than the long-poll window, log transient SSL/network disconnects as warnings, apply exponential backoff with recovery logging, and only escalate to error after five consecutive failures.

tests/test_telegram.py

@@ -87,6 +87,7 @@ def test_get_updates_and_answer():
     data = transport.calls[0]["data"]
     assert data["offset"] == 99
     assert data["timeout"] == 17
+    assert transport.calls[0]["timeout"] == 32
     assert json.loads(data["allowed_updates"]) == ["callback_query"]
 
     transport = FakeTransport(result=True)
@@ -203,6 +204,52 @@ def test_answer_failure_falls_back_to_text():
     assert bot.edits == [10]
 
 
+class Recorder:
+    def __init__(self):
+        self.events = []
+
+    def _add(self, level, event, fields):
+        self.events.append((level, event, fields))
+
+    def info(self, event, **fields):
+        self._add("info", event, fields)
+
+    def warning(self, event, **fields):
+        self._add("warning", event, fields)
+
+    def error(self, event, **fields):
+        self._add("error", event, fields)
+
+    def debug(self, event, **fields):
+        self._add("debug", event, fields)
+
+
+class FlakyBot(FakeBot):
+    def __init__(self):
+        super().__init__([])
+        self.calls = 0
+
+    def get_updates(self, offset=None):
+        self.calls += 1
+        if self.calls < 3:
+            raise OSError("SSL: UNEXPECTED_EOF_WHILE_READING")
+        return []
+
+
+def test_poller_backoff_and_recovery():
+    sleeps = []
+    recorder = Recorder()
+    bot = FlakyBot()
+    poller = TelegramPoller(
+        bot, FakeActions(), logger=recorder, sleeper=sleeps.append
+    )
+    poller.run_forever(initial_delay=3, max_delay=60, max_iterations=3)
+    assert bot.calls == 3
+    assert sleeps == [3, 6]
+    assert [event[0] for event in recorder.events[:2]] == ["warning", "warning"]
+    assert any(event[1] == "telegram.poll_recovered" for event in recorder.events)
+
+
 def main():
     test_format_duration()
     test_send_candidates_and_chunking()
@@ -211,6 +258,7 @@ def main():
     test_telegram_error_description_preserved()
     test_poller_dispatch_and_authorization()
     test_answer_failure_falls_back_to_text()
+    test_poller_backoff_and_recovery()
     print("OK: Telegram 消息、分片、长轮询与回调授权测试全部通过")