feat(cron+tests): extend origin fallback to email/dingtalk/qqbot + fix Weixin test mocks

Cron origin fallback extension (builds on #9193's _HOME_TARGET_ENV_VARS):
adds the three remaining origin-fallback-eligible platforms that have
home channel env vars configured in gateway/config.py but use non-generic
env var names:

- email    → EMAIL_HOME_ADDRESS   (non-standard suffix)
- dingtalk → DINGTALK_HOME_CHANNEL
- qqbot    → QQ_HOME_CHANNEL      (non-standard prefix: QQ_ not QQBOT_)

Picks up the completeness intent of @Xowiek's PR #11317 using the
architecturally-correct dict-based lookup from #9193, so platforms with
non-standard env var names actually resolve instead of silently missing.
Extended the parametrized regression test to cover the new three.

Weixin test mock alignment (builds on #10091's _send_session split):
Three test sites added in Batch 1 (TestWeixinSendImageFileParameterName)
and Batch 3 (TestWeixinVoiceSending) mocked only adapter._session, but
#10091 switched the send paths to check self._send_session. Added the
companion setter so the tests stay green with the session split in place.

cron/scheduler.py

@@ -59,10 +59,13 @@ _HOME_TARGET_ENV_VARS = {
     "signal": "SIGNAL_HOME_CHANNEL",
     "mattermost": "MATTERMOST_HOME_CHANNEL",
     "sms": "SMS_HOME_CHANNEL",
+    "email": "EMAIL_HOME_ADDRESS",
+    "dingtalk": "DINGTALK_HOME_CHANNEL",
     "feishu": "FEISHU_HOME_CHANNEL",
     "wecom": "WECOM_HOME_CHANNEL",
     "weixin": "WEIXIN_HOME_CHANNEL",
     "bluebubbles": "BLUEBUBBLES_HOME_CHANNEL",
+    "qqbot": "QQ_HOME_CHANNEL",
 }
 
 from cron.jobs import get_due_jobs, mark_job_run, save_job_output, advance_next_run

tests/cron/test_scheduler.py

@@ -71,9 +71,12 @@ class TestResolveDeliveryTarget:
             ("signal", "SIGNAL_HOME_CHANNEL", "+15551234567"),
             ("mattermost", "MATTERMOST_HOME_CHANNEL", "team-town-square"),
             ("sms", "SMS_HOME_CHANNEL", "+15557654321"),
+            ("email", "EMAIL_HOME_ADDRESS", "home@example.com"),
+            ("dingtalk", "DINGTALK_HOME_CHANNEL", "cidNNN"),
             ("feishu", "FEISHU_HOME_CHANNEL", "oc_home"),
             ("wecom", "WECOM_HOME_CHANNEL", "wecom-home"),
             ("weixin", "WEIXIN_HOME_CHANNEL", "wxid_home"),
+            ("qqbot", "QQ_HOME_CHANNEL", "group-openid-home"),
         ],
     )
     def test_origin_delivery_without_origin_falls_back_to_supported_home_channels(
@@ -88,10 +91,13 @@ class TestResolveDeliveryTarget:
             "SIGNAL_HOME_CHANNEL",
             "MATTERMOST_HOME_CHANNEL",
             "SMS_HOME_CHANNEL",
+            "EMAIL_HOME_ADDRESS",
+            "DINGTALK_HOME_CHANNEL",
             "BLUEBUBBLES_HOME_CHANNEL",
             "FEISHU_HOME_CHANNEL",
             "WECOM_HOME_CHANNEL",
             "WEIXIN_HOME_CHANNEL",
+            "QQ_HOME_CHANNEL",
         ):
             monkeypatch.delenv(fallback_env, raising=False)
         monkeypatch.setenv(env_var, chat_id)

tests/gateway/test_weixin.py

@@ -527,6 +527,7 @@ class TestWeixinSendImageFileParameterName:
         """Verify send_image_file accepts image_path and forwards to send_document."""
         adapter = _make_adapter()
         adapter._session = object()
+        adapter._send_session = adapter._session
         adapter._token = "test-token"
 
         send_document_mock.return_value = weixin.SendResult(success=True, message_id="test-id")
@@ -554,6 +555,7 @@ class TestWeixinSendImageFileParameterName:
         """Verify send_image_file works with minimal required params."""
         adapter = _make_adapter()
         adapter._session = object()
+        adapter._send_session = adapter._session
         adapter._token = "test-token"
 
         send_document_mock.return_value = weixin.SendResult(success=True, message_id="test-id")
@@ -578,6 +580,7 @@ class TestWeixinVoiceSending:
     def _connected_adapter(self) -> WeixinAdapter:
         adapter = _make_adapter()
         adapter._session = object()
+        adapter._send_session = adapter._session
         adapter._token = "test-token"
         adapter._base_url = "https://weixin.example.com"
         adapter._token_store.get = lambda account_id, chat_id: "ctx-token"