chore(gateway): 调小 Postgres 连接池默认值

- max_connections 100 → 20
- idle_timeout 60s → 30s
- .env.example 补充连接池相关变量注释

.env.example

@@ -52,3 +52,8 @@ ADMIN_PASSWORD=admin123456
 
 # docker compose 下 app 启动前自动执行 pending migration/backfill（默认 true）
 # AETHER_GATEWAY_AUTO_PREPARE_DATABASE=true
+
+# PostgreSQL 连接池配置（默认适合单实例/小型部署；高并发可按需调大）
+# AETHER_GATEWAY_DATA_POSTGRES_MIN_CONNECTIONS=1
+# AETHER_GATEWAY_DATA_POSTGRES_MAX_CONNECTIONS=20
+# AETHER_GATEWAY_DATA_POSTGRES_IDLE_TIMEOUT_MS=30000

apps/aether-gateway/src/main.rs

@@ -170,7 +170,7 @@ struct GatewayDataArgs {
     #[arg(
         long,
         env = "AETHER_GATEWAY_DATA_POSTGRES_MAX_CONNECTIONS",
-        default_value_t = 100
+        default_value_t = 20
     )]
     postgres_max_connections: u32,
 
@@ -184,7 +184,7 @@ struct GatewayDataArgs {
     #[arg(
         long,
         env = "AETHER_GATEWAY_DATA_POSTGRES_IDLE_TIMEOUT_MS",
-        default_value_t = 60_000
+        default_value_t = 30_000
     )]
     postgres_idle_timeout_ms: u64,
 
@@ -1243,9 +1243,9 @@ mod tests {
                 redis_url: None,
                 redis_key_prefix: None,
                 postgres_min_connections: 1,
-                postgres_max_connections: 100,
+                postgres_max_connections: 20,
                 postgres_acquire_timeout_ms: 10_000,
-                postgres_idle_timeout_ms: 60_000,
+                postgres_idle_timeout_ms: 30_000,
                 postgres_max_lifetime_ms: 1_800_000,
                 postgres_statement_cache_capacity: 100,
                 postgres_require_ssl: false,

crates/aether-data/src/postgres/pool.rs

@@ -21,9 +21,9 @@ impl Default for PostgresPoolConfig {
         Self {
             database_url: String::new(),
             min_connections: 1,
-            max_connections: 100,
+            max_connections: 20,
             acquire_timeout_ms: 10_000,
-            idle_timeout_ms: 60_000,
+            idle_timeout_ms: 30_000,
             max_lifetime_ms: 30 * 60_000,
             statement_cache_capacity: 100,
             require_ssl: false,