fix(bluebubbles): apply the require_mention gate before downloading attachments

`_handle_webhook` ran `_collect_attachments` (one REST download per attachment)
before the `is_group and self.require_mention` check, so every attachment on an
unmentioned group message was fetched onto the host and then dropped. The gate
only needs the text, which is available pre-download, so it now runs first;
the "(attachment)" placeholder and the missing-fields check follow the download
as before.

Same class as the Teams fix in this PR (review follow-up). One invariant test:
unmentioned group record with an attachment -> 0 `_download_attachment` calls,
mentioned -> 1 and dispatched.

gateway/platforms/bluebubbles.py

@@ -579,19 +579,21 @@ class BlueBubblesAdapter(BasePlatformAdapter):
         if isinstance(assoc_type, int) and assoc_type in _TAPBACK_CODES:  # tapback reactions delivered as messages
             return _ok()
         text = self._value(record.get("text"), record.get("message"), record.get("body")) or ""
-        media_urls, media_types, msg_type = await self._collect_attachments(record)
-        if not text and media_urls:
-            text = "(attachment)"
         chat_guid, chat_identifier, sender = self._resolve_chat_and_sender(payload, record)
-        if not sender or not (chat_guid or chat_identifier) or not text:
-            return web.json_response({"error": "missing message fields"}, status=400)
         session_chat_id = chat_guid or chat_identifier
         is_group = bool(record.get("isGroup")) or (";+;" in (chat_guid or ""))
+        # Mention gate BEFORE the attachment downloads: an unmentioned group message must not
+        # pull every attachment through the REST API only to be dropped.
         if is_group and self.require_mention:
             if not self._message_matches_mention_patterns(text):
                 logger.debug("[bluebubbles] ignoring group message (require_mention=true, no mention pattern matched)")
                 return _ok()
             text = self._clean_mention_text(text)
+        media_urls, media_types, msg_type = await self._collect_attachments(record)
+        if not text and media_urls:
+            text = "(attachment)"
+        if not sender or not (chat_guid or chat_identifier) or not text:
+            return web.json_response({"error": "missing message fields"}, status=400)
         source = self.build_source(chat_id=session_chat_id, chat_name=chat_identifier or sender,
                                    chat_type="group" if is_group else "dm", user_id=sender, user_name=sender,
                                    chat_id_alt=chat_identifier)

tests/gateway/test_bluebubbles.py

@@ -1,6 +1,7 @@
 """Tests for the BlueBubbles iMessage gateway adapter."""
 import asyncio
 import json
+from unittest.mock import AsyncMock
 
 import httpx
 import pytest
@@ -567,3 +568,41 @@ class TestBlueBubblesTimeoutErrorNormalization:
         assert "500 Internal Server Error" in (result.error or "")
 
 
+
+
+class TestBlueBubblesGateBeforeDownload:
+    """The require_mention gate must run BEFORE attachments are downloaded (review follow-up)."""
+
+    @pytest.mark.asyncio
+    @pytest.mark.parametrize("text, downloads, handled_count", [
+        ("look at this", 0, 0),          # unmentioned group attachment: never fetched
+        ("hermes look at this", 1, 1),   # mentioned: fetched and dispatched
+    ])
+    async def test_unmentioned_group_attachment_is_not_downloaded(
+            self, monkeypatch, text, downloads, handled_count):
+        adapter = _make_adapter(monkeypatch, require_mention=True, send_read_receipts=False)
+        handled = []
+
+        async def fake_handle_message(event):
+            handled.append(event)
+
+        download = AsyncMock(return_value="/tmp/cached.jpg")
+        monkeypatch.setattr(adapter, "handle_message", fake_handle_message)
+        monkeypatch.setattr(adapter, "_download_attachment", download)
+        response = await adapter._handle_webhook(_FakeBlueBubblesRequest({
+            "type": "new-message",
+            "data": {
+                "guid": "msg-att-1",
+                "text": text,
+                "handle": {"address": "+15555550100"},
+                "isFromMe": False,
+                "isGroup": True,
+                "chats": [{"guid": "iMessage;+;group-chat"}],
+                "attachments": [{"guid": "att-1", "mimeType": "image/jpeg"}],
+            },
+        }))
+        await asyncio.sleep(0)
+
+        assert response.status == 200
+        assert download.await_count == downloads
+        assert len(handled) == handled_count