feat(ai): Phase 1C 管理看板 — 用量/成本/功能开关三合一

- UsageService 新增 get_daily_usage + aggregate_daily 日聚合能力
- 新增 3 个管理端点: /ai/admin/daily-usage, /ai/admin/flags (GET+POST)
- AiUsageDashboard 扩展为三 Tab: 用量概览/成本分析/功能开关
- 功能开关支持 Switch 实时切换，权限码 ai.admin.flags
- 日聚合用量 30 天趋势表，含 Token/成本汇总统计

crates/erp-ai/src/service/usage.rs

@@ -5,6 +5,7 @@ use uuid::Uuid;
 
 use crate::entity::ai_analysis;
 use crate::entity::ai_usage;
+use crate::entity::ai_usage_daily;
 use crate::error::AiResult;
 
 pub struct UsageService {
@@ -76,6 +77,85 @@ impl UsageService {
             .await?;
         Ok(result)
     }
+
+    /// 按日期范围查询日聚合用量
+    pub async fn get_daily_usage(
+        &self,
+        tenant_id: Uuid,
+        start_date: chrono::NaiveDate,
+        end_date: chrono::NaiveDate,
+    ) -> AiResult<Vec<DailyUsageRow>> {
+        let rows = ai_usage_daily::Entity::find()
+            .filter(ai_usage_daily::Column::TenantId.eq(tenant_id))
+            .filter(ai_usage_daily::Column::Date.gte(start_date))
+            .filter(ai_usage_daily::Column::Date.lte(end_date))
+            .all(&self.db)
+            .await?;
+        Ok(rows
+            .into_iter()
+            .map(|r| DailyUsageRow {
+                date: r.date,
+                feature: r.feature,
+                provider: r.provider,
+                model: r.model,
+                total_calls: r.total_calls,
+                total_input_tokens: r.total_input_tokens,
+                total_output_tokens: r.total_output_tokens,
+                total_cost_cents: r.total_cost_cents,
+            })
+            .collect())
+    }
+
+    /// 聚合指定日期的用量到日聚合表（由定时任务调用）
+    pub async fn aggregate_daily(&self, tenant_id: Uuid, date: chrono::NaiveDate) -> AiResult<()> {
+        let date_start = date.and_hms_opt(0, 0, 0).unwrap_or_default();
+        let date_end = date_start + chrono::Duration::days(1);
+
+        // 从 ai_usage 按分析类型聚合
+        #[derive(Debug, FromQueryResult)]
+        struct AggRow {
+            analysis_type: String,
+            total_calls: i64,
+            total_input_tokens: i64,
+            total_output_tokens: i64,
+            total_cost_cents: i64,
+        }
+
+        let rows: Vec<AggRow> = ai_usage::Entity::find()
+            .filter(ai_usage::Column::TenantId.eq(tenant_id))
+            .filter(ai_usage::Column::CreatedAt.gte(date_start))
+            .filter(ai_usage::Column::CreatedAt.lt(date_end))
+            .select_only()
+            .column(ai_usage::Column::AnalysisType)
+            .column_as(ai_usage::Column::Id.count(), "total_calls")
+            .column_as(ai_usage::Column::InputTokens.sum(), "total_input_tokens")
+            .column_as(ai_usage::Column::OutputTokens.sum(), "total_output_tokens")
+            .column_as(ai_usage::Column::CostCents.sum(), "total_cost_cents")
+            .group_by(ai_usage::Column::AnalysisType)
+            .into_model::<AggRow>()
+            .all(&self.db)
+            .await?;
+
+        for row in &rows {
+            let id = Uuid::now_v7();
+            let active = ai_usage_daily::ActiveModel {
+                id: Set(id),
+                tenant_id: Set(tenant_id),
+                date: Set(date),
+                feature: Set(row.analysis_type.clone()),
+                provider: Set("aggregated".into()),
+                model: Set("mixed".into()),
+                total_calls: Set(row.total_calls as i32),
+                total_input_tokens: Set(row.total_input_tokens),
+                total_output_tokens: Set(row.total_output_tokens),
+                total_cost_cents: Set(row.total_cost_cents),
+                created_at: Set(chrono::Utc::now()),
+            };
+            active.insert(&self.db).await?;
+        }
+
+        Ok(())
+    }
 }
 
 #[derive(Debug, FromQueryResult)]
@@ -88,3 +168,15 @@ pub struct TypeCount {
     pub analysis_type: String,
     pub count: i64,
 }
+
+#[derive(Debug, Clone, serde::Serialize)]
+pub struct DailyUsageRow {
+    pub date: chrono::NaiveDate,
+    pub feature: String,
+    pub provider: String,
+    pub model: String,
+    pub total_calls: i32,
+    pub total_input_tokens: i64,
+    pub total_output_tokens: i64,
+    pub total_cost_cents: i64,
+}