Convert quarto-website into an extension, fold connectwidgets-example into it

Convert quarto-website into an extension that serves as a viewer-OAuth Content Hub. Fold in relevant pants of connectwidgets-example: the "list my content" role via client-side OJS/JS hitting the public GET /v1/content (per-viewer via the browser session), before deleting standalone connectwidgets-example.

Note: Do not import connectwidgets because it uses non-public APIs that we don’t want to continue exposing/supporting.

Here is a non-exhaustive list of things we'll want to make sure are completed:

• README: rewrite into a genuinely useful doc: what the tool does, who it's for, setup/configuration, and how to use it.
• Well-commented source: comments should explain the why, not just the what.
• Title: in Framework: Functionality form.
• Description: concise; states the functionality and value. Where relevant, names a themed industry with an "applies to any …" cue.

Start by reading the existing quarto-website and connectwidgets-example implementations, focusing on the client-side OJS/JS flow and the public GET /v1/content endpoint used with the browser session. Done means the functionality is folded into the extension, standalone connectwidgets-example is removed, and the README, source comments, title, and description meet the stated requirements without importing connectwidgets.