feat(node): expose OAuth connection config (#3587)

Expose the merged Rust OAuth header provider through the Node/TypeScript
connection path.

Includes:
- Native OAuthConfig conversion for napi-rs
- ConnectionOptions.oauthConfig plumbing
- Public TypeScript OAuthConfig and OAuthFlowType exports
- Generated TypeScript API docs for the new config surface
- input-validation and debug-redaction coverage in the Rust binding
layer

Local validation: cargo fmt --all; git diff --check.

nodejs/lancedb/index.ts

@@ -52,6 +52,7 @@ export {
   SplitHashOptions,
   SplitSequentialOptions,
   ShuffleOptions,
+  OAuthConfig as NativeOAuthConfig,
 } from "./native.js";
 
 export {
@@ -130,6 +131,8 @@ export {
   TokenResponse,
 } from "./header";
 
+export { OAuthConfig, OAuthFlowType } from "./oauth";
+
 export { MergeInsertBuilder, WriteExecutionOptions } from "./merge";
 
 export * as embedding from "./embedding";

nodejs/lancedb/oauth.ts

@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-FileCopyrightText: Copyright The LanceDB Authors
+
+/**
+ * OAuth authentication flow types.
+ */
+export enum OAuthFlowType {
+  /** Client Credentials grant (service-to-service / M2M). */
+  ClientCredentials = "client_credentials",
+  /** Azure Managed Identity via IMDS. */
+  AzureManagedIdentity = "azure_managed_identity",
+}
+
+/**
+ * OAuth configuration for LanceDB authentication.
+ *
+ * This is the public TypeScript OAuth configuration type. The generated
+ * `NativeOAuthConfig` type has the same runtime shape but is an implementation
+ * detail of the napi-rs binding.
+ *
+ * All token acquisition and refresh is handled in the Rust layer.
+ * This config is passed through to Rust via napi-rs.
+ *
+ * @example Client Credentials (service-to-service):
+ * ```typescript
+ * const config: OAuthConfig = {
+ *   issuerUrl: "https://login.microsoftonline.com/{tenant}/v2.0",
+ *   clientId: "app-id",
+ *   clientSecret: "secret",
+ *   scopes: ["api://lancedb-api/.default"],
+ * };
+ * ```
+ *
+ * @example Azure Managed Identity:
+ * ```typescript
+ * const config: OAuthConfig = {
+ *   issuerUrl: "https://login.microsoftonline.com/{tenant}/v2.0",
+ *   clientId: "app-id",
+ *   scopes: ["api://lancedb-api/.default"],
+ *   flow: OAuthFlowType.AzureManagedIdentity,
+ * };
+ * ```
+ */
+export interface OAuthConfig {
+  /**
+   * OIDC issuer URL or OAuth authority URL.
+   * For Azure: `https://login.microsoftonline.com/{tenant_id}/v2.0`
+   */
+  issuerUrl: string;
+
+  /** Application / Client ID. */
+  clientId: string;
+
+  /**
+   * OAuth scopes to request.
+   * For Azure managed identity, exactly one scope or resource is required.
+   * For example: `["api://{app_id}/.default"]`
+   */
+  scopes: string[];
+
+  /** Authentication flow (default: ClientCredentials). */
+  flow?: OAuthFlowType;
+
+  /** Client secret (required for ClientCredentials). */
+  clientSecret?: string;
+
+  /** Client ID for user-assigned managed identity (AzureManagedIdentity). */
+  managedIdentityClientId?: string;
+
+  /**
+   * Seconds before expiry to trigger proactive refresh (default: 300).
+   * Keep this well below the token TTL; if it is greater than or equal to
+   * the TTL, each request refreshes the token.
+   */
+  refreshBufferSecs?: number;
+}