Request runtime and lifetimes

The server builds the Layer passed to ERSC.make once and releases it at shutdown. Its services have application lifetime.

Each HTTP request has an independent Effect scope. Server Function handlers run in the HTTP request fiber. Page, Layout, and Component render Effects run in a request-owned render scope.

Closing the response interrupts unfinished request work and runs its finalizers. Acquire request-local resources inside the request Effect so their lifetime follows the request automatically.

Give work that must outlive a request an explicit application-owned scope.