Retire the guardian toggle over a pref nothing reads

The evidence disclosure stopped honouring showEvidenceByDefault in
v1.4.27 and the owner surface retired the control with it — but the
managed-record coach form still offered the switch, silently governing
nothing. Remove the control, the managed-schema pick, the response
field, and the label in all six locales; the strict schema now refuses
the key outright.

src/__tests__/record-settings-configuration.test.ts

@@ -82,7 +82,6 @@ describe("managed record settings configuration contract", () => {
           tone: "warm",
           verbosity: "default",
           excludeMetrics: [],
-          showEvidenceByDefault: false,
           defaultWindow: "allTime",
         },
       },
@@ -100,6 +99,24 @@ describe("managed record settings configuration contract", () => {
     expect(() => parseManagedRecordSettingsPatch(family, patch)).not.toThrow();
   });
 
+  // Watched red: re-adding `showEvidenceByDefault: true` to the managed
+  // coach pick makes the strict schema accept the key again and this
+  // fails. The evidence disclosure stopped honouring the flag in v1.4.27
+  // (F14); a guardian toggle over a pref nothing reads is a dead control.
+  it("refuses the retired showEvidenceByDefault pref", () => {
+    expect(() =>
+      parseManagedRecordSettingsPatch("coach", {
+        preferences: {
+          tone: "warm",
+          verbosity: "default",
+          excludeMetrics: [],
+          defaultWindow: "allTime",
+          showEvidenceByDefault: true,
+        },
+      }),
+    ).toThrow();
+  });
+
   it("uses the complete canonical module inventory for a fresh record", () => {
     expect(Object.keys(MANAGED_RECORD_SETTINGS_MODULE_DEFAULTS)).toEqual(
       WRITABLE_MODULE_KEYS,

src/app/api/record-settings/[family]/route.ts

@@ -139,7 +139,6 @@ export const GET = apiHandler(
             tone: preferences.tone,
             verbosity: preferences.verbosity,
             excludeMetrics: preferences.excludeMetrics,
-            showEvidenceByDefault: preferences.showEvidenceByDefault,
             defaultWindow: preferences.defaultWindow,
             ...(preferences.dataClusters !== undefined
               ? { dataClusters: preferences.dataClusters }
@@ -344,7 +343,6 @@ export const PATCH = apiHandler(
               tone: preferences.tone,
               verbosity: preferences.verbosity,
               excludeMetrics: preferences.excludeMetrics,
-              showEvidenceByDefault: preferences.showEvidenceByDefault,
               defaultWindow: preferences.defaultWindow,
               ...(preferences.dataClusters !== undefined
                 ? { dataClusters: preferences.dataClusters }

src/components/settings/managed-record-settings-section.tsx

@@ -734,7 +734,6 @@ function CoachSettingsForm({
         excludeMetrics: COACH_EXCLUDE_METRICS.filter(
           (metric) => form.get(`exclude-${metric}`) === "on",
         ),
-        showEvidenceByDefault: form.get("showEvidenceByDefault") === "on",
         defaultWindow: asString(form.get("defaultWindow"), "allTime"),
         ...(form.get("useCustomClusters") === "on"
           ? {
@@ -817,12 +816,6 @@ function CoachSettingsForm({
           </NativeSelect>
         </label>
       </div>
-      <ManagedSwitchRow
-        name="showEvidenceByDefault"
-        label={t("settings.sharedRecord.managedSettings.coach.showEvidence")}
-        defaultChecked={preferences.showEvidenceByDefault === true}
-        disabled={disabled}
-      />
       <fieldset className="space-y-2">
         <legend className="text-sm font-medium">
           {t("settings.sharedRecord.managedSettings.coach.excludedMetrics")}

src/lib/record-settings/configuration.ts

@@ -124,7 +124,6 @@ const managedCoachPreferencesSchema = coachPrefsSchema
     tone: true,
     verbosity: true,
     excludeMetrics: true,
-    showEvidenceByDefault: true,
     defaultWindow: true,
     dataClusters: true,
   })