fix: correct API key cost calculation and UI display issues

- Fix admin panel cost display for "all time" period using permanent Redis key
- Fix user statistics total cost limit to show complete history
- Fix restricted models list overflow with scrollable container

Backend changes:
- src/routes/admin/apiKeys.js: Use allTimeCost for timeRange='all' instead of scanning TTL keys
- src/routes/apiStats.js: Prioritize permanent usage:cost:total key over monthly keys

Frontend changes:
- web/admin-spa/src/components/apistats/LimitConfig.vue: Add overflow-visible and scrolling to model list

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/routes/admin/apiKeys.js

@@ -945,6 +945,30 @@ async function calculateKeyStats(keyId, timeRange, startDate, endDate) {
       allTimeCost = parseFloat((await client.get(totalCostKey)) || '0')
     }
 
+    // 🔧 FIX: 对于 "全部时间" 时间范围，直接使用 allTimeCost
+    // 因为 usage:*:model:daily:* 键有 30 天 TTL，旧数据已经过期
+    if (timeRange === 'all' && allTimeCost > 0) {
+      logger.debug(`📊 使用 allTimeCost 计算 timeRange='all': ${allTimeCost}`)
+
+      return {
+        requests: 0, // 旧数据详情不可用
+        tokens: 0,
+        inputTokens: 0,
+        outputTokens: 0,
+        cacheCreateTokens: 0,
+        cacheReadTokens: 0,
+        cost: allTimeCost,
+        formattedCost: CostCalculator.formatCost(allTimeCost),
+        // 实时限制数据（始终返回，不受时间范围影响）
+        dailyCost,
+        currentWindowCost,
+        windowRemainingSeconds,
+        windowStartTime,
+        windowEndTime,
+        allTimeCost
+      }
+    }
+
     // 只在启用了窗口限制时查询窗口数据
     if (rateLimitWindow > 0) {
       const costCountKey = `rate_limit:cost:${keyId}`