img-17: cache image-only posts; news pipeline notes

tests/test_spec_imgcache.py

@@ -158,6 +158,28 @@ class TestGeneratedImagesCached(OpsBase):
             self.assertEqual(rows[0]["user"], "assistant")
 
 
+class TestImageOnlyMessages(OpsBase):
+    async def test_image_only_post_cached_no_reply(self):
+        """IMG-17: attachment without text -> cached + observed, no reply."""
+        with tempfile.TemporaryDirectory() as tmp:
+            store, cache = make_cache(tmp)
+            self.bot.airesponder.image_cache = cache
+            self.bot.airesponder.observe_event = AsyncMock()
+            self.bot.respond = AsyncMock()
+            message = self.public_msg("")
+            message.content = ""
+            message.channel.name = "chat"
+            attachment = Mock()
+            attachment.url = "https://cdn.discordapp.com/attachments/1/2/silent.png"
+            message.attachments = [attachment]
+            message.id = 77
+            with patch.object(ImageCache, "_download", new_callable=AsyncMock, return_value=PNG):
+                await self.bot.on_message(message)
+            self.assertEqual(len(store.images_recent("chat", 5)), 1)
+            self.bot.airesponder.observe_event.assert_awaited_once()
+            self.bot.respond.assert_not_awaited()
+
+
 class TestContextAnnouncesImages(unittest.IsolatedAsyncioTestCase):
     def test_suffix_mentions_picture_edit(self):
         """IMG-16: cached channel images are announced in the context suffix."""