feat(queue): 增加非文本模型分布式准入队列

使用 PostgreSQL 统一同步与异步非文本任务的并发准入、持久化等待和 Worker 容量分配，并将生产 API 与独立 Worker 角色拆分。

补充策略管理、共享契约、OpenAPI、Kubernetes 双节点 Worker 清单及跨节点验收脚本；未默认启用任何生产 queue_size 策略。

已在原基线完成 Go、前端、迁移、Shell、Kustomize 与长任务容量验收；合入最新主干后将重新执行发布门禁。

apps/api/internal/store/postgres.go

@@ -76,7 +76,11 @@ var (
 )
 
 func Connect(ctx context.Context, databaseURL string) (*Store, error) {
-	config, err := postgresPoolConfig(databaseURL)
+	return ConnectWithMaxConns(ctx, databaseURL, 0)
+}
+
+func ConnectWithMaxConns(ctx context.Context, databaseURL string, maxConns int) (*Store, error) {
+	config, err := postgresPoolConfig(databaseURL, maxConns)
 	if err != nil {
 		return nil, err
 	}
@@ -91,13 +95,16 @@ func Connect(ctx context.Context, databaseURL string) (*Store, error) {
 	return &Store{pool: pool}, nil
 }
 
-func postgresPoolConfig(databaseURL string) (*pgxpool.Config, error) {
+func postgresPoolConfig(databaseURL string, maxConns ...int) (*pgxpool.Config, error) {
 	config, err := pgxpool.ParseConfig(databaseURL)
 	if err != nil {
 		return nil, err
 	}
 	config.ConnConfig.ConnectTimeout = postgresConnectTimeout
 	config.ConnConfig.RuntimeParams["application_name"] = postgresApplicationName
+	if len(maxConns) > 0 && maxConns[0] > 0 {
+		config.MaxConns = int32(maxConns[0])
+	}
 	return config, nil
 }
 
@@ -523,6 +530,8 @@ type GatewayTask struct {
 	AsyncMode                     bool           `json:"asyncMode"`
 	RiverJobID                    int64          `json:"riverJobId,omitempty"`
 	Status                        string         `json:"status"`
+	QueueKey                      string         `json:"-"`
+	Priority                      int            `json:"-"`
 	Cancellable                   *bool          `json:"cancellable,omitempty"`
 	Submitted                     *bool          `json:"submitted,omitempty"`
 	Message                       string         `json:"message,omitempty"`
@@ -570,7 +579,8 @@ COALESCE(api_key_id, ''), COALESCE(api_key_name, ''), COALESCE(api_key_prefix, '
 COALESCE(user_group_id::text, ''), COALESCE(user_group_key, ''), model,
 COALESCE(model_type, ''), COALESCE(requested_model, ''), COALESCE(resolved_model, ''), COALESCE(request_id, ''),
 COALESCE(conversation_id::text, ''), COALESCE(new_message_count, 0),
-request, COALESCE(async_mode, false), COALESCE(river_job_id, 0), status, COALESCE(attempt_count, 0),
+request, COALESCE(async_mode, false), COALESCE(river_job_id, 0), status,
+COALESCE(queue_key, 'default'), COALESCE(priority, 100), COALESCE(attempt_count, 0),
 COALESCE(remote_task_id, ''), COALESCE(remote_task_payload, '{}'::jsonb),
 COALESCE(result, '{}'::jsonb), COALESCE(billings, '[]'::jsonb),
 COALESCE(usage, '{}'::jsonb), COALESCE(metrics, '{}'::jsonb), COALESCE(billing_summary, '{}'::jsonb),
@@ -715,6 +725,11 @@ ORDER BY COALESCE(dynamic_priority, priority) ASC, priority ASC, created_at DESC
 }
 
 func (s *Store) CreatePlatform(ctx context.Context, input CreatePlatformInput) (Platform, error) {
+	normalizedPolicy, err := NormalizeAndValidateRateLimitPolicy(input.RateLimitPolicy)
+	if err != nil {
+		return Platform{}, err
+	}
+	input.RateLimitPolicy = normalizedPolicy
 	credentials, _ := json.Marshal(emptyObjectIfNil(input.Credentials))
 	config, _ := json.Marshal(emptyObjectIfNil(input.Config))
 	retryPolicy, _ := json.Marshal(emptyObjectIfNil(input.RetryPolicy))
@@ -734,7 +749,7 @@ func (s *Store) CreatePlatform(ctx context.Context, input CreatePlatformInput) (
 	var retryPolicyBytes []byte
 	var rateLimitPolicyBytes []byte
 	var dynamicPriority sql.NullInt64
-	err := s.pool.QueryRow(ctx, `
+	err = s.pool.QueryRow(ctx, `
 INSERT INTO integration_platforms (
   provider, platform_key, name, internal_name, base_url, auth_type, credentials, config,
   default_pricing_mode, default_discount_factor, pricing_rule_set_id,
@@ -789,6 +804,11 @@ RETURNING id::text, provider, platform_key, name, COALESCE(internal_name, ''), C
 }
 
 func (s *Store) UpdatePlatform(ctx context.Context, id string, input CreatePlatformInput) (Platform, error) {
+	normalizedPolicy, err := NormalizeAndValidateRateLimitPolicy(input.RateLimitPolicy)
+	if err != nil {
+		return Platform{}, err
+	}
+	input.RateLimitPolicy = normalizedPolicy
 	var credentials any
 	if input.Credentials != nil {
 		credentialsBytes, _ := json.Marshal(emptyObjectIfNil(input.Credentials))
@@ -812,7 +832,7 @@ func (s *Store) UpdatePlatform(ctx context.Context, id string, input CreatePlatf
 	var retryPolicyBytes []byte
 	var rateLimitPolicyBytes []byte
 	var dynamicPriority sql.NullInt64
-	err := s.pool.QueryRow(ctx, `
+	err = s.pool.QueryRow(ctx, `
 UPDATE integration_platforms
 SET provider = $2,
     platform_key = COALESCE(NULLIF($3, ''), platform_key),
@@ -2138,6 +2158,8 @@ func scanGatewayTask(scanner taskScanner) (GatewayTask, error) {
 		&task.AsyncMode,
 		&task.RiverJobID,
 		&task.Status,
+		&task.QueueKey,
+		&task.Priority,
 		&task.AttemptCount,
 		&task.RemoteTaskID,
 		&remoteTaskPayloadBytes,