docs(changeset): stop the operator section restating the summary

Per the writing-changesets skill, per-audience sections must extend the
summary rather than repeat it. The operator paragraph led with "the auth
service now logs ... failures", duplicating the summary line. Reword it
to open with what's actually new to operators: why these failures were
previously invisible (posted straight to the endpoint, no request
logging).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: aspiers

.changeset/log-otp-verification-failures.md

@@ -6,7 +6,7 @@ Failed sign-in code entries now show up in the server logs, split by reason and
 
 **Affects:** Operators
 
-**Operators:** the auth service now logs the sign-in code failures that the browser posts straight to `/api/auth/sign-in/email-otp`, which previously reached no log at all.
+**Operators:** these failures come from the browser posting straight to `/api/auth/sign-in/email-otp`, which the auth service mounts with no request logging, so until now they were invisible.
 
 - Each failure is logged under the `auth:better-auth` logger name (all levels are visible at the default `info` level, no `LOG_LEVEL` change needed). The log message is self-contained and distinct per reason, so you can tell the failures apart at a glance without inspecting a separate field:
   - `OTP verification failed: code expired` — logged at `info` (routine user error)