Reading: nullable facts stay null, non-finite numbers and malformed
buffers fail as bad format, every opening failure reaches the error
screen, cancel holds across awaits, one bad file never hides the list.

Playback: alive/dead follows whichever of round start, health and death
came last; quiet streams hold a living player in place; the dead stay
where they fell; speed carries fractional milliseconds; the score counts
the round being watched once it ends.

Capture: refuses non-finite frames before writing, starts a new strategy
if the old one was deleted or moved to another map, and Open lands on
the page just captured. The replay reclaims the editor's map and marker
settings when the user comes back from the editor.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>