Feature Request: add PDF document viewer

[Denny09310]

Problem

No way to display a PDF inside a Blazor page using the design system. Apps currently fall back to the browser's native viewer, which can't be styled/sized, isn't controllable from code, fires no events, and can't show in-memory documents (no URL).

Proposal

A component that renders PDFs to <canvas> with the library's standard toolbar, controllable via parameters/methods, working on Server, WASM, and Auto.

<BbPdfViewer Url="https://example.com/contract.pdf" Height="600px" />

Parameters

Parameter	Type	Default	Purpose
Url	string?	null	Remote document; changing reloads, clearing empties the viewer
Toolbar	bool	true	Hide for embed-style use (methods still work)
DefaultScale / MinScale / MaxScale	double	1.25 / 0.5 / 3.0	Initial zoom + bounds
Height	string?	"640px"	Canvas height; null fills parent
Class / Id / AriaLabel / AdditionalAttributes	—	—	Standard attributes
OnDocumentLoaded	EventCallback<int>	—	Page count after load
OnPageChanged	EventCallback<PdfViewerPageChangeEventArgs>	—	Page + PageCount on change

Methods (usable with Toolbar="false"): PreviousPageAsync, NextPageAsync, GoToPageAsync(int), ZoomInAsync, ZoomOutAsync, SetScaleAsync(double), FitToWidthAsync(), LoadDataAsync(byte[]|Stream) (no URL/network), DownloadAsync(string?), GetCurrentPageAsync(), GetPageCountAsync(), GetScaleAsync()

Out of scope

Text selection, annotations/bookmarks/outline, continuous scroll, password-encrypted documents.