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

relaykit/relayconvert/convmeta/options.go

@@ -0,0 +1,79 @@
+package convmeta
+
+// Options is the per-request snapshot of host configuration that converters
+// consult. The host fills it from its settings system when constructing the
+// Meta (see relaycommon.RelayInfo.ConvOptions); relaykit users fill it
+// directly. Zero value = every adaptation disabled, no defaults applied.
+type Options struct {
+	Claude ClaudeOptions
+	Gemini GeminiOptions
+
+	// OpenRouterDialect marks the upstream as OpenRouter's OpenAI-compatible
+	// surface, which accepts extra fields (reasoning config, cache_control on
+	// system parts) that converters emit only for that dialect. The host sets
+	// it from the channel type.
+	OpenRouterDialect bool
+
+	// PreserveThinkingSuffix reports models whose -thinking/-nothinking/effort
+	// suffix must be kept on the outgoing model name (host blacklist lookup).
+	// Nil means "never preserve".
+	PreserveThinkingSuffix func(modelName string) bool
+}
+
+type ClaudeOptions struct {
+	// ThinkingAdapterEnabled turns "-thinking"-suffixed OpenAI model names
+	// into Claude extended-thinking requests.
+	ThinkingAdapterEnabled bool
+	// ThinkingAdapterBudgetTokensPercentage sizes thinking budget_tokens as a
+	// fraction of max_tokens when the adapter fires.
+	ThinkingAdapterBudgetTokensPercentage float64
+	// DefaultMaxTokens returns the max_tokens to inject when the source
+	// request carries none. The Claude Messages API requires max_tokens
+	// (omitting it is a 400), so when this hook is nil and no other path
+	// supplies a value, OpenAI→Claude request conversion fails with an
+	// explicit error instead of emitting a request the upstream is
+	// guaranteed to reject. The new-api host always provides this hook;
+	// standalone relaykit users must supply one or guarantee max_tokens on
+	// every request.
+	DefaultMaxTokens func(modelName string) int
+}
+
+type GeminiOptions struct {
+	// ThinkingAdapterEnabled maps -thinking/-nothinking/effort suffixes to
+	// Gemini thinkingConfig.
+	ThinkingAdapterEnabled bool
+	// ThinkingAdapterBudgetTokensPercentage sizes thinkingBudget as a fraction
+	// of maxOutputTokens when the adapter fires.
+	ThinkingAdapterBudgetTokensPercentage float64
+	// FunctionCallThoughtSignatureEnabled attaches thoughtSignature bypass
+	// values to function-call parts.
+	FunctionCallThoughtSignatureEnabled bool
+	// SupportsImagine reports whether the model supports image generation
+	// (switches response modalities). Nil means "never".
+	SupportsImagine func(modelName string) bool
+	// SafetySetting returns the harm threshold for a category. Nil or empty
+	// return means no safetySettings are attached.
+	SafetySetting func(category string) string
+}
+
+func (o *ClaudeOptions) DefaultMaxTokensFor(modelName string) (int, bool) {
+	if o == nil || o.DefaultMaxTokens == nil {
+		return 0, false
+	}
+	return o.DefaultMaxTokens(modelName), true
+}
+
+func (o *GeminiOptions) SupportsImagineModel(modelName string) bool {
+	return o != nil && o.SupportsImagine != nil && o.SupportsImagine(modelName)
+}
+
+func (o *GeminiOptions) SafetySettingFor(category string) string {
+	if o == nil || o.SafetySetting == nil {
+		return ""
+	}
+	return o.SafetySetting(category)
+}
+
+func (o *Options) ShouldPreserveThinkingSuffix(modelName string) bool {
+	return o != nil && o.PreserveThinkingSuffix != nil && o.PreserveThinkingSuffix(modelName)
+}