Expand undocumented SDK types into function docs

## Problem

Some SDK parameter types (e.g. `SwapParams`, `SwapQuote`) appear as opaque type names in the generated docs without their properties expanded into the parameter table. Users have to look up the source to understand what fields to pass.

## Solution

Update `generate-sdk-components.ts` to detect when a top-level parameter's type is a named type alias or interface, and automatically expand its properties as nested `params.x` rows in the parameter table — the same way `@param params.amount` entries work today, but without requiring explicit JSDoc tags for each field.

## Context

The recent fix to resolve nested param types (e.g. `params.signer` → `LocalAccount`) only fills in types for params that already have `@param` JSDoc entries. Types that lack per-field JSDoc (like swap params) still show as a single row with just the type name.