v4.22.0

Focus: Agent-ready at parse time — instant WebMCP registration and restored agent-discovery Link headers.

Changes

• 🌐 Parse-time WebMCP registration: SSR builds now bake an inline head script that registers the WebMCP tools (search_docs, get_page, navigate_to, copy_current_page) the moment the HTML parser reaches it — measured t+445ms on Slow 3G versus t+8.9s with runtime-only registration, which landed past agent checkers' evaluation budget. Execute calls made before the app boots are queued and bridged to the real implementations once the app connects; tool metadata lives in one pure shared module used by both the prerenderer and the runtime
• 🔗 Fixed the homepage's agent-discovery Link headers (api-catalog, service-doc, service-desc, describedby) being clobbered: Cloudflare Pages lets the last _headers rule matching a path own a header name, and the appended Early Hints block for / replaced the agent block — the prerenderer now merges its Link/Cache-Control lines into existing path blocks
• ✅ Validated with a live agent-readiness scan, an emulated navigator.modelContext environment (registration timing, queued execution navigating for real) and new manifest/inline-script specs; 342 tests passing