Message Logger: comments of deleted channel posts

The comments button of a deleted post opens the app's own comments section
(discussion thread), its history request answered locally from the logged
comments; the input bar is replaced by a "Viewing deleted comments" notice.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/api.py

@@ -54,6 +54,12 @@ class Api:
         except requests.RequestException as exc:
             raise ApiError(f"Server unreachable: {exc}") from exc
         if response.status_code == 404:
+            try:
+                detail = response.json().get("detail")
+            except Exception:
+                detail = None
+            if detail == "Not Found":  # the route itself: an older server
+                raise ApiError("the server doesn't support this yet (update telegram-panel)")
             return None
         if response.status_code >= 400:
             try:
@@ -127,6 +133,13 @@ class Api:
             params={"account_id": account_id},
         )
 
+    def comments(self, account_id, chat_id, message_id):
+        return self._first(
+            "GET",
+            f"/messages/{chat_id}/{message_id}/comments",
+            params={"account_id": account_id},
+        )
+
     def deletions(self, account_id, chat_id, message_ids):
         ids = sorted(set(int(i) for i in message_ids))
         marked = 0