app: add storage commands/queries + missing in-memory test repos

crates/application/src/storage/queries/check_quota.rs

@@ -0,0 +1,45 @@
+use std::sync::Arc;
+use domain::{
+    entities::UsageType,
+    errors::DomainError,
+    ports::{QuotaRepository, UsageLedgerRepository},
+    storage::services::{check_quota, QuotaCheckResult},
+    value_objects::SystemId,
+};
+
+#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
+pub struct CheckQuotaQuery {
+    pub user_id: SystemId,
+    pub usage_type: UsageType,
+    pub requested_amount: u64,
+}
+
+pub struct CheckQuotaHandler {
+    quota_repo: Arc<dyn QuotaRepository>,
+    ledger_repo: Arc<dyn UsageLedgerRepository>,
+}
+
+impl CheckQuotaHandler {
+    pub fn new(
+        quota_repo: Arc<dyn QuotaRepository>,
+        ledger_repo: Arc<dyn UsageLedgerRepository>,
+    ) -> Self {
+        Self { quota_repo, ledger_repo }
+    }
+
+    pub async fn execute(&self, query: CheckQuotaQuery) -> Result<QuotaCheckResult, DomainError> {
+        let quota = self.quota_repo.find_by_owner(&query.user_id).await?;
+
+        let Some(quota) = quota else {
+            return Ok(QuotaCheckResult {
+                allowed: true,
+                current_usage: 0,
+                limit: 0,
+                is_unlimited: true,
+            });
+        };
+
+        let current = self.ledger_repo.sum_usage(&query.user_id, query.usage_type, None).await?;
+        Ok(check_quota(&quota, query.usage_type, current, query.requested_amount))
+    }
+}