Update/polish 5 extensions

We want to make sure the Gallery content is useful/compelling for users. We have 5 published extensions that we want to make sure are up to date, and have clear explanations for users:

• chat-with-content
• package-vulnerability-scanner
• publisher-command-center
• content-health-monitor
• runtime-version-scanner

Here is a non-exhaustive list of things we'll want to make sure are completed for these 5:

• Title & description: a plain, capability-forward product name (e.g. "Package Vulnerability Scanner"), NOT a "Framework: Functionality" title. The framework is an implementation detail here, not the identity. Keep the description concise, stating the functionality and value.
• README: rewrite into a genuinely useful doc (most are 1–2 liners today): what the tool does, who it's for, setup/configuration, and how to use it.
• Self-demonstrating output + a "how this works" panel: surface the otherwise-invisible mechanism in the app's own UI. For the OAuth/identity/governance tools especially: make the mechanism the content (e.g. "signed in as {you}, resolved from your session, no admin key stored").
• Well-commented source: comments should explain the why, not just the what.

For content-health-monitor, we can fold in the functionality of prototype-content-with-issues-table (surfaces content whose latest deployment/job has failed), before then deleting prototype-content-with-issues-table. content-health-monitor becomes a single scheduled content-health report covering both content/URL uptime and failed deployments/jobs We could optionally also roll a third prong into the new-and-improved content-health-monitor: surfacing orphaned content (content owned by deactivated/departed users or that's been unused/unviewed for a long time).

Start by locating the five published extensions, their README files, source, and UI entry points, along with prototype-content-with-issues-table. Review the current Gallery presentation and document the required updates for each extension. Done means all five have clear names, useful READMEs, self-demonstrating output, and why-focused comments, with the prototype functionality addressed before its removal.