fix(web): Domain.templateId опционален (Go omitempty), String() на error

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web/src/api/client.ts

@@ -12,7 +12,7 @@ async function req<T>(path: string, init?: RequestInit): Promise<T> {
   })
   if (!res.ok) {
     let msg = `HTTP ${res.status}`
-    try { const b = await res.json(); if (b?.error) msg = b.error } catch { /* ignore */ }
+    try { const b = await res.json(); if (b?.error) msg = String(b.error) } catch { /* ignore */ }
     throw new Error(msg)
   }
   if (res.status === 204) return undefined as T

web/src/api/types.ts

@@ -10,7 +10,7 @@ export interface Domain {
   providerAccountId: string
   zoneName: string
   zoneId: string
-  templateId: string | null
+  templateId?: string | null // Go omitempty: поле может отсутствовать (undefined), а не null
 }
 export interface CreateDomainInput {
   providerAccountId: string