fix(channel-monitor-v2): preserve migration checksums and privacy defaults

backend/internal/server/api_contract_test.go

@@ -977,7 +977,7 @@ func TestAPIContracts(t *testing.T) {
 					"account_quota_notify_emails": [],
 					"channel_monitor_enabled": true,
 					"channel_monitor_mode": "v2",
-					"channel_monitor_hide_throughput": false,
+					"channel_monitor_hide_throughput": true,
 					"channel_monitor_default_interval_seconds": 60,
 					"available_channels_enabled": false,
 					"model_plaza_enabled": false,
@@ -1282,7 +1282,7 @@ func TestAPIContracts(t *testing.T) {
 					"account_quota_notify_emails": [],
 					"channel_monitor_enabled": true,
 					"channel_monitor_mode": "v2",
-					"channel_monitor_hide_throughput": false,
+					"channel_monitor_hide_throughput": true,
 					"channel_monitor_default_interval_seconds": 60,
 					"available_channels_enabled": false,
 					"model_plaza_enabled": false,

backend/internal/service/setting_public.go

@@ -352,7 +352,7 @@ func (s *SettingService) GetPublicSettings(ctx context.Context) (*PublicSettings
 		ChannelMonitorEnabled:                !isFalseSettingValue(settings[SettingKeyChannelMonitorEnabled]),
 		ChannelMonitorMode:                   normalizeChannelMonitorMode(settings[SettingKeyChannelMonitorMode]),
 		ChannelMonitorDefaultIntervalSeconds: parseChannelMonitorInterval(settings[SettingKeyChannelMonitorDefaultIntervalSeconds]),
-		ChannelMonitorHideThroughput:         settings[SettingKeyChannelMonitorHideThroughput] == "true",
+		ChannelMonitorHideThroughput:         !isFalseSettingValue(settings[SettingKeyChannelMonitorHideThroughput]),
 
 		AvailableChannelsEnabled: settings[SettingKeyAvailableChannelsEnabled] == "true",
 
@@ -461,7 +461,7 @@ func (s *SettingService) GetChannelMonitorRuntime(ctx context.Context) ChannelMo
 		Enabled:                !isFalseSettingValue(vals[SettingKeyChannelMonitorEnabled]),
 		Mode:                   normalizeChannelMonitorMode(vals[SettingKeyChannelMonitorMode]),
 		DefaultIntervalSeconds: parseChannelMonitorInterval(vals[SettingKeyChannelMonitorDefaultIntervalSeconds]),
-		HideThroughput:         vals[SettingKeyChannelMonitorHideThroughput] != "false",
+		HideThroughput:         !isFalseSettingValue(vals[SettingKeyChannelMonitorHideThroughput]),
 	}
 }
 

backend/internal/service/setting_service_public_test.go

@@ -101,6 +101,21 @@ func TestSettingService_GetPublicSettings_ExposesCompactHomeEnabled(t *testing.T
 	require.False(t, missingSettings.CompactHomeEnabled)
 }
 
+func TestSettingService_ChannelMonitorHideThroughputDefaultsToPrivate(t *testing.T) {
+	missing := NewSettingService(&settingPublicRepoStub{values: map[string]string{}}, &config.Config{}).GetChannelMonitorRuntime(context.Background())
+	require.True(t, missing.HideThroughput)
+	public, err := NewSettingService(&settingPublicRepoStub{values: map[string]string{}}, &config.Config{}).GetPublicSettings(context.Background())
+	require.NoError(t, err)
+	require.True(t, public.ChannelMonitorHideThroughput)
+
+	for _, value := range []string{"false", "0", "off", "disabled"} {
+		runtime := NewSettingService(&settingPublicRepoStub{values: map[string]string{
+			SettingKeyChannelMonitorHideThroughput: value,
+		}}, &config.Config{}).GetChannelMonitorRuntime(context.Background())
+		require.False(t, runtime.HideThroughput, "value=%q", value)
+	}
+}
+
 func TestSettingService_GetPublicSettings_ExposesForceEmailOnThirdPartySignup(t *testing.T) {
 	repo := &settingPublicRepoStub{
 		values: map[string]string{

backend/migrations/203_channel_monitor_v2_default_ignore_and_cache.sql

@@ -1,9 +1,7 @@
 -- Factory presets for Channel Monitor V2 config:
 -- 1) ignored_error_categories: non-ops client/policy failures that should not
 --    dominate health error_rate by default (still shown greyed in breakdown).
--- 2) health_thresholds cache floors are intentionally left at the tolerant
---    zero/zero defaults from migration 198. Platforms without prompt caching
---    must not be marked unhealthy by factory configuration.
+-- 2) health_thresholds cache floors: 85% watch / 60% critical (higher is better).
 --
 -- Only apply when the row still looks like factory empty ignore list and/or
 -- zero cache thresholds (operator customizations are left alone).
@@ -21,3 +19,13 @@ SET ignored_error_categories = ARRAY[
 ]::text[]
 WHERE id = 1
   AND COALESCE(cardinality(ignored_error_categories), 0) = 0;
+
+UPDATE channel_monitor_v2_config
+SET health_thresholds = health_thresholds
+    || jsonb_build_object(
+        'warning_cache_rate', 0.85,
+        'critical_cache_rate', 0.60
+    )
+WHERE id = 1
+  AND COALESCE((health_thresholds->>'warning_cache_rate')::float8, 0) = 0
+  AND COALESCE((health_thresholds->>'critical_cache_rate')::float8, 0) = 0;

backend/migrations/204_channel_monitor_hide_throughput.sql

@@ -1,5 +1,5 @@
 -- Soft switch: hide RPM/TPM throughput rates on user-facing Channel Monitor V2.
--- Default true (rates hidden). Admins always see full metrics.
+-- Default false (rates visible). Admins always see full metrics.
 INSERT INTO settings (key, value)
-VALUES ('channel_monitor_hide_throughput', 'true')
+VALUES ('channel_monitor_hide_throughput', 'false')
 ON CONFLICT (key) DO NOTHING;

backend/migrations/206_channel_monitor_v2_privacy_defaults.sql

@@ -0,0 +1,8 @@
+-- Correct factory defaults introduced by migrations 203 and 204 without
+-- mutating those already-applied migration files (which are checksum-locked).
+-- The setting was factory-created as false by migration 204. Existing
+-- installations need the same privacy-preserving default as new installs.
+UPDATE settings
+SET value = 'true', updated_at = NOW()
+WHERE key = 'channel_monitor_hide_throughput'
+  AND LOWER(TRIM(value)) IN ('false', '0', 'off', 'disabled');