test(gateway): cover photo burst interrupt regressions

Add regression coverage for non-album Telegram photo burst batching, photo follow-ups that should queue without interrupting active runs, and the gateway priority-interrupt path for photo events.

tests/gateway/test_telegram_photo_interrupts.py

@@ -0,0 +1,49 @@
+import asyncio
+from unittest.mock import MagicMock
+
+import pytest
+
+from gateway.config import GatewayConfig, Platform, PlatformConfig
+from gateway.platforms.base import MessageEvent, MessageType
+from gateway.session import SessionSource, build_session_key
+from gateway.run import GatewayRunner
+
+
+class _PendingAdapter:
+    def __init__(self):
+        self._pending_messages = {}
+
+
+def _make_runner():
+    runner = object.__new__(GatewayRunner)
+    runner.config = GatewayConfig(platforms={Platform.TELEGRAM: PlatformConfig(enabled=True, token="***")})
+    runner.adapters = {Platform.TELEGRAM: _PendingAdapter()}
+    runner._running_agents = {}
+    runner._pending_messages = {}
+    runner._pending_approvals = {}
+    runner._voice_mode = {}
+    runner._is_user_authorized = lambda _source: True
+    return runner
+
+
+@pytest.mark.asyncio
+async def test_handle_message_does_not_priority_interrupt_photo_followup():
+    runner = _make_runner()
+    source = SessionSource(platform=Platform.TELEGRAM, chat_id="12345", chat_type="dm")
+    session_key = build_session_key(source)
+    running_agent = MagicMock()
+    runner._running_agents[session_key] = running_agent
+
+    event = MessageEvent(
+        text="caption",
+        message_type=MessageType.PHOTO,
+        source=source,
+        media_urls=["/tmp/photo-a.jpg"],
+        media_types=["image/jpeg"],
+    )
+
+    result = await runner._handle_message(event)
+
+    assert result is None
+    running_agent.interrupt.assert_not_called()
+    assert runner.adapters[Platform.TELEGRAM]._pending_messages[session_key] is event