fix(teams): log reply() fallback for diagnostics

The previous bare except swallowed every exception from app.reply()
silently. Log at debug so real failures (auth, chat gone) leave a
trace while keeping the group-chat 400 fallback working. Also fix
the Teams entry's indentation in the messaging flowchart.

website/docs/user-guide/messaging/index.md

@@ -60,9 +60,9 @@ flowchart TB
     bb[BlueBubbles]
     qq[QQ]
     yb[Yuanbao]
-            ms[Microsoft Teams]
-            api["API Server<br/>(OpenAI-compatible)"]
-            wh[Webhooks]
+    ms[Microsoft Teams]
+    api["API Server<br/>(OpenAI-compatible)"]
+    wh[Webhooks]
         end
 
         store["Session store<br/>per chat"]