fix(data): 同步模型调用次数至 global_models 读模型

- 模型列表改为读取 global_models.usage_count，避免每次扫描 usage 明细表
- 通过历史 backfill 与 usage upsert delta 维护该读模型
- 详情页保留实时 facts 兜底，统一排除 pending/streaming 状态

crates/aether-data/src/repository/global_models/sql.rs

@@ -405,7 +405,7 @@ SELECT
   gm.config,
   COALESCE(gm_stats.provider_count, 0) AS provider_count,
   COALESCE(gm_stats.active_provider_count, 0) AS active_provider_count,
-  COALESCE(gm.usage_count, 0)::bigint AS usage_count,
+  COALESCE(usage_stats.usage_count, gm.usage_count, 0)::bigint AS usage_count,
   EXTRACT(EPOCH FROM gm.created_at)::bigint AS created_at_unix_ms,
   EXTRACT(EPOCH FROM gm.updated_at)::bigint AS updated_at_unix_secs
 FROM global_models gm
@@ -423,6 +423,12 @@ LEFT JOIN (
   JOIN providers p ON p.id = m.provider_id
   GROUP BY m.global_model_id
 ) gm_stats ON gm_stats.global_model_id = gm.id
+LEFT JOIN LATERAL (
+  SELECT NULLIF(COUNT(*), 0)::bigint AS usage_count
+  FROM usage_billing_facts AS usage
+  WHERE usage.model = gm.name
+    AND usage.status NOT IN ('pending', 'streaming')
+) usage_stats ON TRUE
 WHERE gm.id = $1
 LIMIT 1
             "#,
@@ -452,7 +458,7 @@ SELECT
   gm.config,
   COALESCE(gm_stats.provider_count, 0) AS provider_count,
   COALESCE(gm_stats.active_provider_count, 0) AS active_provider_count,
-  COALESCE(gm.usage_count, 0)::bigint AS usage_count,
+  COALESCE(usage_stats.usage_count, gm.usage_count, 0)::bigint AS usage_count,
   EXTRACT(EPOCH FROM gm.created_at)::bigint AS created_at_unix_ms,
   EXTRACT(EPOCH FROM gm.updated_at)::bigint AS updated_at_unix_secs
 FROM global_models gm
@@ -470,6 +476,12 @@ LEFT JOIN (
   JOIN providers p ON p.id = m.provider_id
   GROUP BY m.global_model_id
 ) gm_stats ON gm_stats.global_model_id = gm.id
+LEFT JOIN LATERAL (
+  SELECT NULLIF(COUNT(*), 0)::bigint AS usage_count
+  FROM usage_billing_facts AS usage
+  WHERE usage.model = gm.name
+    AND usage.status NOT IN ('pending', 'streaming')
+) usage_stats ON TRUE
 WHERE gm.name = $1
 LIMIT 1
             "#,
@@ -1205,7 +1217,10 @@ fn map_provider_active_global_model_row(
 
 #[cfg(test)]
 mod tests {
-    use super::{SqlxGlobalModelReadRepository, LIST_ADMIN_PROVIDER_MODELS_PREFIX};
+    use super::{
+        SqlxGlobalModelReadRepository, LIST_ADMIN_GLOBAL_MODELS_PREFIX,
+        LIST_ADMIN_PROVIDER_MODELS_PREFIX,
+    };
     use crate::postgres::{PostgresPoolConfig, PostgresPoolFactory};
 
     const ADMIN_PROVIDER_MODEL_REQUIRED_COLUMNS: &[&str] = &[
@@ -1241,6 +1256,64 @@ mod tests {
         );
     }
 
+    #[test]
+    fn admin_global_model_sql_projects_usage_count_from_billing_facts() {
+        let source = include_str!("sql.rs");
+
+        assert!(
+            !LIST_ADMIN_GLOBAL_MODELS_PREFIX.contains("usage_billing_facts"),
+            "admin global model list should read the maintained usage_count field"
+        );
+        assert!(
+            source.contains("WHERE usage.model = gm.name"),
+            "admin global model detail lookups should count usage facts for the selected model"
+        );
+        assert!(
+            source.contains("AND usage.status NOT IN ('pending', 'streaming')"),
+            "admin global model detail usage_count should use the maintained read-model status scope"
+        );
+        assert!(
+            source.contains("COALESCE(usage_stats.usage_count, gm.usage_count, 0)::bigint AS usage_count"),
+            "admin global model usage_count should prefer actual usage facts with stored-count fallback"
+        );
+    }
+
+    #[test]
+    fn admin_global_model_list_sql_counts_usage_without_full_fact_aggregate() {
+        assert!(
+            LIST_ADMIN_GLOBAL_MODELS_PREFIX.contains("COALESCE(gm.usage_count, 0)::bigint AS usage_count"),
+            "admin global model list should read maintained usage_count without per-request fact scans"
+        );
+        assert!(
+            !LIST_ADMIN_GLOBAL_MODELS_PREFIX.contains("GROUP BY usage.model"),
+            "admin global model list must not aggregate the full usage fact table before pagination"
+        );
+    }
+
+    #[test]
+    fn global_model_usage_count_read_model_has_backfill_and_delta_maintenance() {
+        let backfill_sql =
+            include_str!("../../../backfills/20260505120000_rebuild_global_model_usage_count.sql");
+        let delta_sql = include_str!("../usage/sql/queries/apply_global_model_usage_delta_sql.sql");
+
+        assert!(
+            backfill_sql.contains("UPDATE global_models AS gm"),
+            "global model usage_count backfill should refresh the read model"
+        );
+        assert!(
+            backfill_sql.contains("FROM usage_billing_facts AS usage"),
+            "global model usage_count backfill should rebuild from canonical usage facts"
+        );
+        assert!(
+            delta_sql.contains("UPDATE global_models"),
+            "usage writes should maintain the global model usage_count read model"
+        );
+        assert!(
+            delta_sql.contains("WHERE name = $1"),
+            "global model usage_count delta should target models by canonical model name"
+        );
+    }
+
     #[tokio::test]
     async fn repository_constructs_from_lazy_pool() {
         let factory = PostgresPoolFactory::new(PostgresPoolConfig {