Autoplay Core

Sets up the shared Autoplay SDK foundation for live user activity in an existing customer stack. Covers installing autoplay-sdk, registering a product to get ingest_url/ingest_secret/mcp_url/mcp_key, the default REST/MCP pull pattern for AI agents, and the legacy push/session-linking path used only where explicitly required. Use when starting any Autoplay integration or when the user mentions autoplay-sdk, mcp_key, onboard_product, live activity, or MCP.