style(admin-web): apply blurred-backdrop cover treatment to KOL cards

Switch KOL package, template, and workspace card covers from object-fit
cover to a blurred backdrop with a contained foreground image so non-16:9
artwork no longer crops awkwardly. Also restyle the package detail back
button, swap the generate-button copy for the canonical key, and rename
"prompts" counts to "refined templates" in i18n.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/admin-web/src/i18n/messages/en-US.ts

@@ -194,7 +194,7 @@ const enUS = {
       },
       empty: "No published subscription packages yet",
       subscribers: "{count} subscribed tenants",
-      prompts: "{count} prompts",
+      prompts: "{count} refined templates",
     },
     package: {
       subscribe: "Request subscription",

apps/admin-web/src/i18n/messages/zh-CN.ts

@@ -194,7 +194,7 @@ const zhCN = {
       },
       empty: "暂无已上架的订阅包",
       subscribers: "{count} 个订阅租户",
-      prompts: "{count} 个提示词",
+      prompts: "{count} 个精调模版",
     },
     package: {
       subscribe: "申请订阅",