fix(billing): 封住发布前计费竞态

阻止上游提交状态不明的任务被租约接管后重复执行，并为人工复核保留可操作的结算记录。

将生产提交绑定到当前估价签名，统一复用预处理快照，并补强规则形状、定点溢出与历史规则兼容校验。

已通过 PostgreSQL 16 集成测试、Go 全量测试与静态检查、前端测试与构建、OpenAPI、依赖审计、镜像、迁移、流水线和 SemVer 门禁。

apps/api/internal/runner/pricing_v2_test.go

@@ -1,6 +1,8 @@
 package runner
 
 import (
+	"errors"
+	"math"
 	"testing"
 
 	"github.com/easyai/easyai-ai-gateway/apps/api/internal/store"
@@ -16,11 +18,29 @@ func TestFixedAmountPreservesNineDecimalPlaces(t *testing.T) {
 	}
 
 	price := mustFixedAmount(t, "0.000000001")
-	if got, want := price.MulInt(3).String(), "0.000000003"; got != want {
+	product, err := multiplyFixedAmountByInt(price, 3)
+	if err != nil {
+		t.Fatalf("multiply fixed amount: %v", err)
+	}
+	if got, want := product.String(), "0.000000003"; got != want {
 		t.Fatalf("nano amount multiplication=%q, want %q", got, want)
 	}
 }
 
+func TestFixedAmountOperationsRejectOverflow(t *testing.T) {
+	maximum := fixedAmount(math.MaxInt64)
+	if _, err := multiplyFixedAmountByInt(maximum, 2); !errors.Is(err, errFixedAmountOverflow) {
+		t.Fatalf("multiply overflow error=%v", err)
+	}
+	if _, err := addFixedAmounts(maximum, 1); !errors.Is(err, errFixedAmountOverflow) {
+		t.Fatalf("add overflow error=%v", err)
+	}
+	pricing := resolvedPricing{RuleSetID: "overflow-rule"}
+	if _, err := pricing.calculate("image", maximum, []int{2}); !isPricingUnavailable(err) {
+		t.Fatalf("pricing overflow should be unavailable: %v", err)
+	}
+}
+
 func TestEstimatedOutputTokensUsesAliasesAndCapabilityFallback(t *testing.T) {
 	candidate := store.RuntimeModelCandidate{
 		ModelType: "text_generate",
@@ -97,6 +117,27 @@ func TestPricingAvailabilityRequiresExplicitFree(t *testing.T) {
 	}
 }
 
+func TestPricingWeightsUseFixedPrecisionAndRejectInvalidValues(t *testing.T) {
+	pricing := resolvedPricing{Config: map[string]any{
+		"image": map[string]any{
+			"dynamicWeight": map[string]any{
+				"qualityFactors": map[string]any{"high": "1.123456789", "broken": 0},
+			},
+		},
+	}}
+	weight, err := pricing.weight("image", "qualityWeights", "high")
+	if err != nil || weight.String() != "1.123456789" {
+		t.Fatalf("exact weight=%s err=%v", weight.String(), err)
+	}
+	if _, err := pricing.weight("image", "qualityWeights", "broken"); !isPricingUnavailable(err) {
+		t.Fatalf("invalid configured weight should make pricing unavailable: %v", err)
+	}
+	defaultWeight, err := pricing.weight("image", "qualityWeights", "unconfigured")
+	if err != nil || defaultWeight.String() != "1.000000000" {
+		t.Fatalf("default weight=%s err=%v", defaultWeight.String(), err)
+	}
+}
+
 func mustFixedAmount(t *testing.T, value string) fixedAmount {
 	t.Helper()
 	amount, err := parseFixedAmount(value)