Refresh MCP-B organization search surfaces

[MiguelsPizza]

Summary

Updates the public WebMCP-org profile and organization-wide community files so search engines and developers see current MCP-B terminology, working canonical links, and accurate WebMCP guidance.

• strengthens the organization profile title and opening description around MCP-B, WebMCP, website tools, and AI agents
• replaces stale or redirecting docs URLs with current canonical tutorials, explanations, and package pages
• updates examples from the deprecated navigator surface and handler callback to document.modelContext and execute
• removes broken resources such as old best-practices, ai-frameworks, and extension routes
• clarifies that WebMCP is a W3C Community Group proposal, not a W3C Standard
• links the profile, support, contribution, and security pages to the authoritative W3C draft, Chrome guidance, current MCP-B docs, GitHub examples, and npm organization
• removes the outdated community POC extension claim and points contributors to the maintained package source

Why

Google Search Console reports 380 external links, but 91% point to the two homepages. The GitHub organization is already a top linking domain, so direct canonical links from its durable public profile to high-value docs pages improve crawl paths and reduce redirect noise.

Validation

A repository-wide scan of Markdown files confirms the edited public surfaces no longer reference navigator.modelContext or the identified stale/redirecting documentation paths.