feat: 算力引擎 Go 后端核心（new-api）

- 统一 OpenAI 兼容 /v1 中继 + 渠道/额度/令牌/流水
- 各领域包：relay 模型网关、model 数据层、controller 管理 API

relay/alpha_search_handler_test.go

@@ -0,0 +1,47 @@
+package relay
+
+import (
+	"testing"
+
+	"github.com/QuantumNous/new-api/common"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestBuildAlphaSearchRequestBodyPreservesUnknownFields(t *testing.T) {
+	raw := []byte(`{
+		"id":"req_1",
+		"model":"gpt-5.1",
+		"input":[{"role":"user","content":"hi"}],
+		"commands":{"search_query":[{"q":"weather","recency":1}]},
+		"settings":{"locale":"en"},
+		"future_field":{"nested":true}
+	}`)
+
+	out, err := buildAlphaSearchRequestBody(raw, "gpt-5.1", "gpt-5.1-mapped")
+	require.NoError(t, err)
+
+	var body map[string]any
+	require.NoError(t, common.Unmarshal(out, &body))
+	assert.Equal(t, "gpt-5.1-mapped", body["model"])
+	assert.Equal(t, "req_1", body["id"])
+	require.Contains(t, body, "commands")
+	require.Contains(t, body, "settings")
+	require.Contains(t, body, "future_field")
+	require.Contains(t, body, "input")
+
+	commands, ok := body["commands"].(map[string]any)
+	require.True(t, ok)
+	require.Contains(t, commands, "search_query")
+
+	future, ok := body["future_field"].(map[string]any)
+	require.True(t, ok)
+	assert.Equal(t, true, future["nested"])
+}
+
+func TestBuildAlphaSearchRequestBodyNoMappingKeepsRawBytes(t *testing.T) {
+	raw := []byte(`{"model":"gpt-5.1","commands":{"search_query":[{"q":"x"}]},"future_field":1}`)
+	out, err := buildAlphaSearchRequestBody(raw, "gpt-5.1", "gpt-5.1")
+	require.NoError(t, err)
+	assert.Equal(t, raw, out)
+}