Replace radius-only escape termination with a common asymptotic exterior protocol: declared ends, moving escape worldtubes, directed inside->outside crossings, and a PENDING_ENTRY lifecycle shared by single-frame and movie tracing.
Add an analytic Carlson-integral Schwarzschild monopole exterior (angle primitive, bracketed turning radius, ingoing Kerr-Schild coordinate-time transfer, conserved-energy frequency) so a camera outside the escape sphere is traced through an entry event.
Make the lifecycle tri-state (no ends / ready / protocol error), carry end_id through the endpoint and lens mesh, validate sources in constructors via spacetime_source_finalize(), and refresh the Schwarzschild reference images for the corrected finish.
wyj