perf(queue): 按策略动态扩缩异步 Worker

将 River 执行容量按平台模型与用户组的有效并发策略动态调整，并为长任务续租、并发租约原子抢占和限流退避补充保护。\n\n统一平台模型限流继承语义，兼容历史 platformLimits/modelLimits，并为三个迁移图像模型建立独立并发租约。补充管理端显式继承/覆盖配置、指标、单元测试及隔离 PostgreSQL 验收。\n\n验证：go test ./... -count=1；pnpm lint；pnpm test；pnpm build；隔离 PostgreSQL 并发原子性/续租测试；128 任务与三分钟长任务动态 Worker 验收。

apps/api/internal/store/postgres.go

@@ -235,6 +235,8 @@ type PlatformModel struct {
 	Capabilities             map[string]any `json:"capabilities,omitempty"`
 	BaseCapabilities         map[string]any `json:"-"`
 	BaseBillingConfig        map[string]any `json:"-"`
+	BaseRateLimitPolicy      map[string]any `json:"-"`
+	BaseRuntimePolicySetID   string         `json:"-"`
 	BasePricingRuleSetID     string         `json:"-"`
 	PlatformPricingRuleSetID string         `json:"-"`
 	PricingMode              string         `json:"pricingMode"`
@@ -245,6 +247,7 @@ type PlatformModel struct {
 	PermissionConfig         map[string]any `json:"permissionConfig,omitempty"`
 	RetryPolicy              map[string]any `json:"retryPolicy,omitempty"`
 	RateLimitPolicy          map[string]any `json:"rateLimitPolicy,omitempty"`
+	RateLimitPolicyMode      string         `json:"rateLimitPolicyMode" enums:"inherit,override"`
 	RuntimePolicySetID       string         `json:"runtimePolicySetId,omitempty"`
 	RuntimePolicyOverride    map[string]any `json:"runtimePolicyOverride,omitempty"`
 	CooldownUntil            string         `json:"cooldownUntil,omitempty"`
@@ -956,7 +959,9 @@ SELECT m.id::text, m.platform_id::text, COALESCE(m.base_model_id::text, ''), p.p
        COALESCE(b.base_billing_config, '{}'::jsonb), COALESCE(b.pricing_rule_set_id::text, ''),
        COALESCE(p.pricing_rule_set_id::text, ''), m.pricing_mode, COALESCE(m.discount_factor, 0)::float8,
        COALESCE(m.pricing_rule_set_id::text, ''), m.billing_config_override, m.billing_config,
-       m.permission_config, m.retry_policy, m.rate_limit_policy, COALESCE(m.runtime_policy_set_id::text, ''), m.runtime_policy_override,
+       m.permission_config, m.retry_policy, m.rate_limit_policy, m.rate_limit_policy_mode,
+       COALESCE(m.runtime_policy_set_id::text, ''), m.runtime_policy_override,
+       COALESCE(b.default_rate_limit_policy, '{}'::jsonb), COALESCE(b.runtime_policy_set_id::text, ''),
        COALESCE(to_char(m.cooldown_until AT TIME ZONE 'UTC', 'YYYY-MM-DD"T"HH24:MI:SS.MS"Z"'), ''),
        m.enabled, m.created_at, m.updated_at
 FROM platform_models m
@@ -964,6 +969,7 @@ JOIN integration_platforms p ON p.id = m.platform_id
 LEFT JOIN LATERAL (
   SELECT catalog.invocation_name, catalog.display_name, catalog.model_type,
          catalog.capabilities, catalog.base_billing_config, catalog.pricing_rule_set_id,
+         catalog.default_rate_limit_policy, catalog.runtime_policy_set_id,
          COALESCE((
            SELECT jsonb_agg(DISTINCT compatibility_alias.alias ORDER BY compatibility_alias.alias)
            FROM model_compatibility_aliases compatibility_alias
@@ -1004,6 +1010,7 @@ ORDER BY m.model_type ASC, m.model_name ASC`, args...)
 		var retryPolicy []byte
 		var rateLimitPolicy []byte
 		var runtimePolicyOverride []byte
+		var baseRateLimitPolicy []byte
 		var modelTypeBytes []byte
 		var legacyAliasesBytes []byte
 		if err := rows.Scan(
@@ -1032,8 +1039,11 @@ ORDER BY m.model_type ASC, m.model_name ASC`, args...)
 			&permissionConfig,
 			&retryPolicy,
 			&rateLimitPolicy,
+			&model.RateLimitPolicyMode,
 			&model.RuntimePolicySetID,
 			&runtimePolicyOverride,
+			&baseRateLimitPolicy,
+			&model.BaseRuntimePolicySetID,
 			&model.CooldownUntil,
 			&model.Enabled,
 			&model.CreatedAt,
@@ -1053,6 +1063,7 @@ ORDER BY m.model_type ASC, m.model_name ASC`, args...)
 		model.RetryPolicy = decodeObject(retryPolicy)
 		model.RateLimitPolicy = decodeObject(rateLimitPolicy)
 		model.RuntimePolicyOverride = decodeObject(runtimePolicyOverride)
+		model.BaseRateLimitPolicy = decodeObject(baseRateLimitPolicy)
 		models = append(models, model)
 	}
 	return models, rows.Err()