docs: add JSDoc comments to exported router utility functions

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: jameskranz

packages/server/src/router-utils.ts

@@ -10,6 +10,11 @@ import { mergeMiddlewares } from './middleware-utils'
 import { isProcedure, Procedure } from './procedure'
 import { getHiddenRouterContract } from './router-hidden'
 
+/**
+ * Resolves a nested router by walking the given path segments.
+ *
+ * @info If a lazy router is encountered mid-path, the remaining segments are deferred into a new lazy loader.
+ */
 export function getRouter<T extends Lazyable<AnyRouter | undefined>>(
   router: T,
   path: readonly string[],
@@ -57,6 +62,9 @@ export type AccessibleLazyRouter<T extends Lazyable<AnyRouter | undefined>>
         [K in keyof T]: T[K] extends Lazyable<AnyRouter> ? AccessibleLazyRouter<T[K]> : never
       }
 
+/**
+ * Creates a proxy around a lazy router that enables dot-notation property access without eager loading.
+ */
 export function createAccessibleLazyRouter<T extends Lazy<AnyRouter | undefined>>(lazied: T): AccessibleLazyRouter<T> {
   const recursive = new Proxy(lazied, {
     get(target, key) {
@@ -107,6 +115,11 @@ export interface EnhanceRouterOptions<TErrorMap extends ErrorMap> extends Enhanc
   dedupeLeadingMiddlewares: boolean
 }
 
+/**
+ * Recursively applies middlewares, error maps, and route options to every procedure in a router tree.
+ *
+ * @info Lazy routers are wrapped so enhancement is deferred until loading. Non-object primitive values are safely skipped.
+ */
 export function enhanceRouter<
   T extends Lazyable<AnyRouter>,
   TInitialContext extends Context,
@@ -183,6 +196,11 @@ export interface LazyTraverseContractProceduresOptions {
   path: readonly string[]
 }
 
+/**
+ * Synchronously walks a router tree, invoking the callback for each contract procedure and collecting lazy routers for deferred resolution.
+ *
+ * @info Non-object primitive values in the tree are safely skipped.
+ */
 export function traverseContractProcedures(
   options: TraverseContractProceduresOptions,
   callback: (options: TraverseContractProcedureCallbackOptions) => void,
@@ -226,6 +244,9 @@ export function traverseContractProcedures(
   return lazyOptions
 }
 
+/**
+ * Asynchronously resolves all procedures in a router tree, including those behind lazy loaders.
+ */
 export async function resolveContractProcedures(
   options: TraverseContractProceduresOptions,
   callback: (options: TraverseContractProcedureCallbackOptions) => void,
@@ -253,6 +274,11 @@ export type UnlaziedRouter<T extends AnyRouter>
         [K in keyof T]: T[K] extends Lazyable<infer U extends AnyRouter> ? UnlaziedRouter<U> : never
       }
 
+/**
+ * Recursively resolves all lazy-loaded components in a router tree, returning a fully eager copy.
+ *
+ * @info Procedures are returned as-is. Non-object primitive values are safely skipped.
+ */
 export async function unlazyRouter<T extends AnyRouter>(router: T): Promise<UnlaziedRouter<T>> {
   if (isProcedure(router)) {
     return router as any