perf(acceptance): 将 API 连接池提升至 64

P24 千并发在 API Pool 48 下仍出现 acquired 接近上限及 canceled acquire 增长，而 Worker Pool 仅使用 3 条连接，PostgreSQL 实际连接数仍有安全余量。

将生产 API Pool 默认值提升至 64，并允许通过 AI_GATEWAY_ACCEPTANCE_API_DATABASE_MAX_CONNS 配置单次验收；Worker 档位与 min-idle=4 保持不变。

验证：bash -n、ShellCheck、kubectl kustomize 和 git diff --check 通过。

deploy/kubernetes/easyai-ai-gateway-cluster-release

@@ -19,7 +19,7 @@ source "$config_file"
 : "${AI_GATEWAY_ASYNC_WORKER_INSTANCE_HARD_LIMIT:=24}"
 : "${AI_GATEWAY_ASYNC_WORKER_HARD_LIMIT:=48}"
 : "${AI_GATEWAY_DATABASE_MAX_CONNS:=32}"
-: "${AI_GATEWAY_API_DATABASE_MAX_CONNS:=48}"
+: "${AI_GATEWAY_API_DATABASE_MAX_CONNS:=64}"
 : "${AI_GATEWAY_DATABASE_MIN_IDLE_CONNS:=4}"
 : "${AI_GATEWAY_MEDIA_MATERIALIZATION_CONCURRENCY:=24}"
 : "${AI_GATEWAY_MEDIA_REQUEST_CONCURRENCY:=24}"

deploy/kubernetes/easyai-ai-gateway-cluster-release.conf.example

@@ -10,7 +10,7 @@ AI_GATEWAY_WORKER_REPLICAS_HONGKONG=1
 AI_GATEWAY_ASYNC_WORKER_INSTANCE_HARD_LIMIT=24
 AI_GATEWAY_ASYNC_WORKER_HARD_LIMIT=48
 AI_GATEWAY_DATABASE_MAX_CONNS=32
-AI_GATEWAY_API_DATABASE_MAX_CONNS=48
+AI_GATEWAY_API_DATABASE_MAX_CONNS=64
 AI_GATEWAY_DATABASE_MIN_IDLE_CONNS=4
 AI_GATEWAY_MEDIA_MATERIALIZATION_CONCURRENCY=24
 AI_GATEWAY_MEDIA_REQUEST_CONCURRENCY=24

deploy/kubernetes/production/application.yaml

@@ -53,7 +53,7 @@ spec:
             - name: AI_GATEWAY_ASYNC_QUEUE_WORKER_ENABLED
               value: "false"
             - name: AI_GATEWAY_DATABASE_MAX_CONNS
-              value: "48"
+              value: "64"
             - name: AI_GATEWAY_DATABASE_MIN_IDLE_CONNS
               value: "4"
             - name: AI_GATEWAY_MEDIA_REQUEST_CONCURRENCY
@@ -184,7 +184,7 @@ spec:
             - name: AI_GATEWAY_ASYNC_QUEUE_WORKER_ENABLED
               value: "false"
             - name: AI_GATEWAY_DATABASE_MAX_CONNS
-              value: "48"
+              value: "64"
             - name: AI_GATEWAY_DATABASE_MIN_IDLE_CONNS
               value: "4"
             - name: AI_GATEWAY_MEDIA_REQUEST_CONCURRENCY