ref(slack): Fix thread_ts handling and add missing type annotations

Remove the ts fallback from SlackEventRequest.thread_ts so top-level
messages correctly yield None instead of collapsing into the message ts.
Add missing return type annotations to has_assistant_scope and
is_assistant_thread_event. Move variable extraction before org
resolution in _handle_seer_prompt for earlier lifecycle context.

Author: leeandher

src/sentry/integrations/slack/requests/event.py

@@ -75,14 +75,14 @@ def user_id(self) -> str:
     def thread_ts(self) -> str:
         if self.is_assistant_thread_event:
             return self.dm_data.get("assistant_thread", {}).get("thread_ts", "")
-        return self.dm_data.get("thread_ts") or self.dm_data.get("ts", "")
+        return self.dm_data.get("thread_ts")
 
     @property
-    def has_assistant_scope(self):
+    def has_assistant_scope(self) -> bool:
         return SlackScope.ASSISTANT_WRITE in self.integration.metadata.get("scopes", [])
 
     @property
-    def is_assistant_thread_event(self):
+    def is_assistant_thread_event(self) -> bool:
         return self.dm_data.get("type") == "assistant_thread_started"
 
     @property

src/sentry/integrations/slack/webhooks/event.py

@@ -447,10 +447,17 @@ def _handle_seer_prompt(
             spec=SlackMessagingSpec(),
         ).capture() as lifecycle:
             data = slack_request.data.get("event", {})
+            channel_id = data.get("channel")
+            text = data.get("text")
+            ts = data.get("ts") or data.get("message_ts")
+            thread_ts = slack_request.thread_ts
             lifecycle.add_extras(
                 {
                     "integration_id": slack_request.integration.id,
-                    "thread_ts": data.get("thread_ts"),
+                    "thread_ts": thread_ts,
+                    "channel_id": channel_id,
+                    "text": text,
+                    "ts": ts,
                 }
             )
 
@@ -465,21 +472,6 @@ def _handle_seer_prompt(
             organization_id = result["organization_id"]
             installation = result["installation"]
 
-            channel_id = data.get("channel")
-            text = data.get("text")
-            ts = data.get("ts") or data.get("message_ts")
-            thread_ts = data.get("thread_ts")
-
-            lifecycle.add_extras(
-                {
-                    "channel_id": channel_id,
-                    "text": text,
-                    "ts": ts,
-                    "thread_ts": thread_ts,
-                    "user_id": slack_request.user_id,
-                }
-            )
-
             if not channel_id or not text or not ts or not slack_request.user_id:
                 lifecycle.record_halt(SeerSlackHaltReason.MISSING_EVENT_DATA)
                 return self.respond()
@@ -606,6 +598,7 @@ def post(self, request: Request) -> Response:
             command, _ = slack_request.get_command_and_args()
 
             resp: Response | None
+            # If we have the assistant scope, we don't want to fallback to commands anymore.
             if slack_request.has_assistant_scope:
                 resp = self.on_direct_message(slack_request)
             elif command in COMMANDS: