fleetd #638: stop the verdict userinfo mask from crossing / or whitespace

mask_verdict_userinfo's character class [^@]* crossed a '/' or a space, so a
verdict line with a URI that has no userinfo plus a later @ (e.g. an email
address in diagnostic prose) had everything between them destroyed. Restrict
the class to [^@/[:space:]]* so the match stops at the end of the URI.

Adds the uncovered-direction test: a URI with no userinfo plus a later @ in
the same line must pass through byte for byte. Also drops the design-rationale
sentence from the helper's comment (now in the PR description).

scripts/config-edit.sh

@@ -581,11 +581,9 @@ install_candidate() {
 # -------------------------------------------------------------------------------- the report path
 #
 # Masks basic-auth userinfo (scheme://user:pass@host) in a daemon verdict line before it reaches
-# the terminal. Not routed through redact(): that function's key:value masking does not match this
-# line's prose, and masking anything beyond the userinfo would remove the detail an operator needs
-# to diagnose a refusal.
+# the terminal.
 mask_verdict_userinfo() {
-  printf '%s\n' "$1" | sed -E 's#://[^@]*@#://<redacted>@#g'
+  printf '%s\n' "$1" | sed -E 's#://[^@/[:space:]]*@#://<redacted>@#g'
 }
 
 # Prints the literal command the operator (or a test) can run to restore the backup by hand — the

scripts/test-config-edit.sh

@@ -670,6 +670,24 @@ test_ordinary_refusal_line_passes_through_unchanged() {
     "an ordinary refusal with no userinfo must pass through byte for byte, unchanged"
 }
 
+# A verdict line can hold a URI with NO userinfo and a later, unrelated @ further on in the same
+# line (an email address in diagnostic prose, for example). The rewrite must stop at the end of
+# the URI and must not treat the later @ as a second userinfo delimiter.
+test_uri_without_userinfo_survives_a_later_at_sign() {
+  local dir real_line
+  dir="$(new_fixture)"
+  real_line="config reload from $dir/fleetd.yaml refused, keeping the running config: broker.uri amqp://broker.local/vhost unreachable, contact ops@example.com"
+
+  start_run "$dir" 5 --set '.profiles.sonnet.weight=4'
+  sleep 1
+  printf '%s\n' "$real_line" >> "$dir/fleetd.out"
+  collect_run "$dir"
+
+  assert_equals 4 "$RUN_RC" "no-userinfo-with-later-at-sign exit code"
+  assert_contains "$real_line" "$RUN_OUTPUT" \
+    "a URI with no userinfo plus a later @ in the same line must pass through byte for byte"
+}
+
 # --set runs yq over the whole candidate. It warns when that changes more lines than the requested
 # pairs, but a simple file with only the intended changed line must stay quiet.
 new_fixture_reformat_sensitive() {
@@ -765,6 +783,8 @@ echo "== verdict-redaction criteria 2+3: verdict userinfo is masked, rest of lin
 test_verdict_userinfo_is_masked_with_positive_control
 echo "== verdict-redaction criterion 4: an ordinary refusal passes through unchanged =="
 test_ordinary_refusal_line_passes_through_unchanged
+echo "== fleetd #638: a URI with no userinfo survives a later @ in the same line =="
+test_uri_without_userinfo_survives_a_later_at_sign
 echo "== acceptance criterion 17: --set warns about yq formatting churn =="
 test_set_warns_when_yq_reformats_extra_lines
 echo "== acceptance criterion 18: --set stays quiet without formatting churn =="