feat: 添加 gpt-5.4 模型定价和测试用例 (#395)

Author: luodaoyi

internal/pricing/calculator_test.go

@@ -115,6 +115,15 @@ func TestCalculator_Calculate(t *testing.T) {
 			},
 			wantZero: false,
 		},
+		{
+			name:  "gpt-5.4 basic",
+			model: "gpt-5.4",
+			metrics: &usage.Metrics{
+				InputTokens:  50_000,
+				OutputTokens: 5_000,
+			},
+			wantZero: false,
+		},
 		{
 			name:  "gemini-2.5-pro basic",
 			model: "gemini-2.5-pro",
@@ -216,6 +225,7 @@ func TestPriceTable_Get_PrefixMatch(t *testing.T) {
 		{"gpt-5.1-codex", true},
 		{"gpt-5.2", true},
 		{"gpt-5.3", true},
+		{"gpt-5.4", true},
 		{"gemini-2.5-pro", true},
 		{"gemini-2.5-flash", true},
 		{"gemini-3-pro-preview", true},

internal/pricing/default_prices.go

@@ -276,6 +276,14 @@ func initDefaultPrices() *PriceTable {
 		CacheReadPriceMicro: 175_000,    // $0.175/M
 	})
 
+	// gpt-5.4: input=$2.50, cache_read=$0.25, output=$15
+	pt.Set(&ModelPricing{
+		ModelID:             "gpt-5.4",
+		InputPriceMicro:     2_500_000,  // $2.50/M
+		OutputPriceMicro:    15_000_000, // $15.00/M
+		CacheReadPriceMicro: 250_000,    // $0.25/M
+	})
+
 	// ========== GPT-4o 系列 ==========
 	// gpt-4o: input=$2.50, output=$10, cache_read=$1.25
 	pt.Set(&ModelPricing{