fix: logo 右半部分从 CODING 改为 CODE

去掉难以正确渲染的 N 和 G 字母，右半部分简化为 CODE（4 字母），
与左半部分 AIR 组合为 AIR CODE。

packages/llm/src/provider.ts

@@ -0,0 +1,37 @@
+import type { RouteDefaultsInput } from "./route/client"
+import type { Model, ModelID, ProviderID } from "./schema"
+
+export type ModelOptions = RouteDefaultsInput
+
+/**
+ * Advanced structural provider definition helper. Built-in providers should
+ * prefer explicit `configure(options).model(id)` facades so deployment config is
+ * chosen before model selection. The optional `apis` map remains for external
+ * structural providers that expose multiple route selectors behind one provider.
+ */
+export type ModelFactory<Options extends ModelOptions = ModelOptions> = (
+  id: string | ModelID,
+  options?: Options,
+) => Model
+
+type AnyModelFactory = (...args: never[]) => Model
+
+export interface Definition<Factory extends AnyModelFactory = ModelFactory> {
+  readonly id: ProviderID
+  readonly model: Factory
+  readonly apis?: Record<string, AnyModelFactory>
+}
+
+type DefinitionShape = {
+  readonly id: ProviderID
+  readonly model: (...args: never[]) => Model
+  readonly apis?: Record<string, (...args: never[]) => Model>
+}
+
+type NoExtraFields<Input, Shape> = Input & Record<Exclude<keyof Input, keyof Shape>, never>
+
+export const make = <DefinitionType extends DefinitionShape>(
+  definition: NoExtraFields<DefinitionType, DefinitionShape>,
+) => definition
+
+export * as Provider from "./provider"