v4.22.2

Focus: One WebMCP registration API at a time — imperative first, declarative as fallback.

Changes

• 🌐 The WebMCP tools now register through a single API: registerTool when the browser provides it, provideContext only as a fallback — the previous dual mode registered the same tools through both, which chokes agent checkers' declarative verification path
• ✅ Verified in an emulated navigator.modelContext environment (4 registerTool calls, 0 provideContext) plus a fallback-path spec; 343 tests passing