fix(s52): scrub every URL-bearing exception path in WebhookNotifier

src/portfolio_optimiser/notify.py

@@ -18,6 +18,7 @@ from __future__ import annotations
 import json
 import sys
 from collections.abc import Callable
+from http.client import HTTPException
 from pathlib import Path
 from typing import TYPE_CHECKING, Any, Protocol, TextIO, runtime_checkable
 from urllib.error import URLError
@@ -126,10 +127,16 @@ class WebhookNotifier:
     def __call__(self, verdict: Verdict) -> None:
         try:
             self._post(self._url, json.dumps(_verdict_payload(verdict), sort_keys=True))
-        except (URLError, OSError) as exc:
-            # STRICTER than ingest.py:314: the message NEVER carries the url — a Slack/Teams
-            # webhook URL embeds the receiver secret (the original cause stays chained).
-            raise NotifyError("webhook POST failed") from exc
+        except (URLError, OSError, ValueError, HTTPException) as exc:
+            # STRICTER than ingest.py:314: NO exception type may carry the url past this point —
+            # a Slack/Teams webhook URL embeds the receiver secret. The tuple covers every
+            # URL-carrier _urllib_post can raise (ValueError incl. UnicodeError; HTTPException
+            # incl. InvalidURL; OSError incl. URLError/HTTPError/TimeoutError). The chain is
+            # severed (`from None`) because __cause__ renders in tracebacks/logging.exception;
+            # the exception type name in the message is the diagnostic substitute for the lost
+            # chain. Deliberately NOT a bare `except Exception`: the transport is injectable,
+            # and a test transport's AssertionError/TypeError (programming errors) must surface.
+            raise NotifyError(f"webhook POST failed ({type(exc).__name__})") from None
 
 
 # --- config + factory (fail-fast, egress never config-grantable) ----------------------------------