Call the webmail inbuxa-webmail in docs and comments

The webmail repository was renamed from ihasmail-inbuxa to inbuxa-webmail
on 2026-10-05. The OAuth client id stays ihasmail-inbuxa: that is what the
server registers, so the backticked and quoted ids are unchanged.

docs/spec/features/ai-spam-classification.md

@@ -353,7 +353,7 @@ adds at most 2.
 
 ## ihasmail changes
 
-These go in the INBUXA fork of ihasmail, ihasmail-inbuxa, never in public
+These go in the INBUXA fork of ihasmail, inbuxa-webmail, never in public
 ihasmail, which stays Stalwart-facing (SPEC.md §5).
 
 - **Reading:** when a message has an `X-Spam-LLM` header, the message details