Two contact resolution fixes in create conversation:
Under the reuse policy, an unknown external_user_id went straight to
insert. If the email belonged to an existing contact, that inserted a
duplicate contact sharing the email, since the unique email index only
covers rows without an ext_id. The ext_id lookup now falls back to the
email match before inserting. Regression test added.
The new conversation form sends name fields as a snapshot from contact
search, so a contacts:write agent submitting the form could overwrite a
contact that was renamed after the search. The form now sends
reuse_contact: true and the backend downgrades to the reuse policy when
it is set. API callers like an external CRM omit the flag and keep the
full sync/upsert behavior. The flag can only downgrade, never escalate.
Also from review: hoist the repeated password generation block into
newContactPassword, drop testutil.NewLogger and the duplicate
newTestI18n in transcript_test.go in favor of testutil.NewI18n, and
clean up stale comments.
Abhinav Raut