feat: add quota limit for API key accounts

- Add configurable spending limit (quota_limit) for apikey-type accounts
- Atomic quota accumulation via PostgreSQL JSONB operations on TotalCost
- Scheduler filters out over-quota accounts with outbox-triggered snapshot refresh
- Display quota usage ($used / $limit) in account capacity column
- Add "Reset Quota" action in account menu to reset usage to zero
- Editing account settings preserves quota_used (no accidental reset)
- Covers all 3 billing paths: Anthropic, Gemini, OpenAI RecordUsage

chore: bump version to 0.1.90.4

backend/internal/handler/dto/mappers.go

@@ -248,6 +248,17 @@ func AccountFromServiceShallow(a *service.Account) *Account {
 		}
 	}
 
+	// 提取 API Key 账号配额限制（仅 apikey 类型有效）
+	if a.Type == service.AccountTypeAPIKey {
+		if limit := a.GetQuotaLimit(); limit > 0 {
+			out.QuotaLimit = &limit
+		}
+		used := a.GetQuotaUsed()
+		if out.QuotaLimit != nil {
+			out.QuotaUsed = &used
+		}
+	}
+
 	return out
 }