refactor(theming): replace red-* palette with semantic error-* tokens

Sweep 30 files: text/bg/border/ring/from/to/via/fill/stroke/shadow/divide/decoration/
outline/placeholder-red-N → -error-N. All red usages were semantically error/danger
(no brand red), so tokens now flow through the design-system CSS variables and respond
to palette overrides.

src/components/sales-stats/AddonsTab.tsx

@@ -48,7 +48,7 @@ export function AddonsTab({ params }: AddonsTabProps) {
   }
 
   if (isError || !data) {
-    return <div className="py-8 text-center text-red-400">{t('admin.salesStats.loadError')}</div>;
+    return <div className="py-8 text-center text-error-400">{t('admin.salesStats.loadError')}</div>;
   }
 
   const packageBarData = data.by_package.map((item) => ({

src/components/sales-stats/DepositsTab.tsx

@@ -68,7 +68,7 @@ export function DepositsTab({ params }: DepositsTabProps) {
   }
 
   if (isError || !data) {
-    return <div className="py-8 text-center text-red-400">{t('admin.salesStats.loadError')}</div>;
+    return <div className="py-8 text-center text-error-400">{t('admin.salesStats.loadError')}</div>;
   }
 
   return (

src/components/sales-stats/RenewalsTab.tsx

@@ -35,7 +35,7 @@ export function RenewalsTab({ params }: RenewalsTabProps) {
   }
 
   if (isError || !data) {
-    return <div className="py-8 text-center text-red-400">{t('admin.salesStats.loadError')}</div>;
+    return <div className="py-8 text-center text-error-400">{t('admin.salesStats.loadError')}</div>;
   }
 
   const dailyData = data.daily.map((item) => ({

src/components/sales-stats/SalesTab.tsx

@@ -45,7 +45,7 @@ export function SalesTab({ params }: SalesTabProps) {
   }
 
   if (isError || !data) {
-    return <div className="py-8 text-center text-red-400">{t('admin.salesStats.loadError')}</div>;
+    return <div className="py-8 text-center text-error-400">{t('admin.salesStats.loadError')}</div>;
   }
 
   const tariffBarData = data.by_tariff.map((item) => ({

src/components/sales-stats/TrialsTab.tsx

@@ -42,7 +42,7 @@ export function TrialsTab({ params }: TrialsTabProps) {
   }
 
   if (isError || !data) {
-    return <div className="py-8 text-center text-red-400">{t('admin.salesStats.loadError')}</div>;
+    return <div className="py-8 text-center text-error-400">{t('admin.salesStats.loadError')}</div>;
   }
 
   const pieData = data.by_provider.map((item) => ({