A Host startup failure reached the crash report as a fresh Error built from
a message string three hops away from the original: the Host sent only
error.message over the fatal IPC event, DesktopHostProcess wrapped it in a
new Error, desktopErrorState flattened it to text, and main.ts wrapped that
text again. Stack, cause, code, and path were gone, and the Host's stderr
tail arriving with the later exit was blocked by the first-failure latch.
The Host now sends its complete inspected error alongside the message
(bounded to 64 KiB; carried over IPC rather than stderr because the two
race and the shell reports the first failure it sees). DesktopHostProcess
keeps it on DesktopHostFatalError.diagnostic, the backend error state
carries the original failure object, main.ts reports that object, and the
crash report prints the Host diagnostic verbatim in its own section.